98 results on '"Panda SP"'
Search Results
52. Neuroinflammation and neovascularization in diabetic eye diseases (DEDs): identification of potential pharmacotherapeutic targets.
- Author
-
Panda SP, Reddy PH, Gorla US, and Prasanth D
- Subjects
- Humans, Aged, Vascular Endothelial Growth Factor A metabolism, von Willebrand Factor therapeutic use, Poly(ADP-ribose) Polymerase Inhibitors therapeutic use, Neuroinflammatory Diseases, Programmed Cell Death 1 Receptor, Neovascularization, Pathologic drug therapy, Vascular Endothelial Growth Factors, Diabetic Retinopathy metabolism, Diabetes Mellitus drug therapy
- Abstract
The goal of this review is to increase public knowledge of the etiopathogenesis of diabetic eye diseases (DEDs), such as diabetic retinopathy (DR) and ocular angiosarcoma (ASO), and the likelihood of blindness among elderly widows. A widow's life in North India, in general, is fraught with peril because of the economic and social isolation it brings, as well as the increased risk of death from heart disease, hypertension, diabetes, depression, and dementia. Neovascularization, neuroinflammation, and edema in the ocular tissue are hallmarks of the ASO, a rare form of malignant tumor. When diabetes, hypertension, and aging all contribute to increased oxidative stress, the DR can proceed to ASO. Microglia in the retina of the optic nerve head are responsible for causing inflammation, discomfort, and neurodegeneration. Those that come into contact with them will get blind as a result of this. Advanced glycation end products (AGE), vascular endothelial growth factor (VEGF), protein kinase C (PKC), poly-ADP-ribose polymerase (PARP), metalloproteinase9 (MMP9), nuclear factor kappaB (NFkB), program death ligand1 (PDL-1), factor VIII (FVIII), and von Willebrand factor (VWF) are potent agents for ocular neovascularisation (ONV), neuroinflammation and edema in the ocular tissue. AGE/VEGF, DAG/PKC, PARP/NFkB, RAS/VEGF, PDL-1/PD-1, VWF/FVIII/VEGF, and RAS/VEGF are all linked to the pathophysiology of DEDs. The interaction between ONV and ASO is mostly determined by the VWF/FVIII/VEGF and PDL-1/PD-1 axis. This study focused on retinoprotective medications that can pass the blood-retinal barrier and cure DEDs, as well as the factors that influence the etiology of neovascularization and neuroinflammation in the eye., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)
- Published
- 2023
- Full Text
- View/download PDF
53. Role of DPP4 and DPP4i in Glucose Homeostasis and Cardiorenal Syndrome.
- Author
-
Panda SP
- Subjects
- Humans, Hypoglycemic Agents adverse effects, Dipeptidyl Peptidase 4 therapeutic use, Insulin, Glucagon-Like Peptide 1, Glucose, Homeostasis, Dipeptidyl-Peptidase IV Inhibitors pharmacology, Dipeptidyl-Peptidase IV Inhibitors therapeutic use, Diabetes Mellitus, Type 2 drug therapy, Cardio-Renal Syndrome drug therapy, Cardio-Renal Syndrome chemically induced, Hypoglycemia, Myocardial Ischemia chemically induced, Myocardial Ischemia drug therapy
- Abstract
The objective of the review led to the pursuit of adopting dipeptidyl peptidase-4 inhibitors (DPP4i) as a novel pharmacotherapy in diabetes mellitus (DM) and cardiorenal syndrome (CRS). The CRS is defined as the co-existence of myocardial ischemia with renal failure. At present, the commercially available drugs enhance insulin secretion or action. However, most of the drugs are associated with adverse effects, such as weight gain or hypoglycemia. As a result, newer therapies with better safety and efficacy profiles are being explored. The DPP4 protease enzyme is involved in cardiovascular and renal diseases in association with over-expressed cytokines. The novel characteristic of DPP4i is to control the elevated blood glucose levels in response to nutrient ingestion without causing hypoglycemia. Also, DPP4i are indirectly involved in reducing myocardial ischemia by promoting cardioprotective peptides. They protect the glucagon-like peptide 1 (GLP-1) from the deteriorating effect of the DPP4 enzyme. The GLP-1 receptors (GLP-1R) are abundantly expressed in renal and cardiovascular tissue. The overexpression of GLP-1R will confer protection of the heart and kidney during CRS. DPP4i were found to significantly clear plasma glucose by the simultaneously activating natural thrombolytic system and increasing insulin levels. They can be used in the early stages of the disease, including pre-diabetes or obesity combined with impaired incretin response, while the combination of DPP4i with metformin or thiazolidinediones as insulin sensitizers offers an additional improvement in the treatment of DM. With its positive attributes in a host of associated parameters of interest, DPP4i are studied extensively in the present review., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)
- Published
- 2023
- Full Text
- View/download PDF
54. Interlinked role of ASN, TDP-43 and Miro1 with parkinopathy: Focus on targeted approach against neuropathy in parkinsonism.
- Author
-
Panda SP, Prasanth D, Gorla US, and Dewanjee S
- Subjects
- Humans, alpha-Synuclein, DNA-Binding Proteins genetics, Neurodegenerative Diseases, Protein Kinases genetics, Protein Kinases metabolism, Ubiquitin-Protein Ligases genetics, Ubiquitin-Protein Ligases metabolism, rho GTP-Binding Proteins metabolism, Parkinsonian Disorders drug therapy, Parkinsonian Disorders genetics
- Abstract
Parkinsonism is a complex neurodegenerative disease that is difficult to differentiate because of its idiopathic and unknown origins. The hereditary parkinsonism known as autosomal recessive-juvenile parkinsonism (AR-JP) is marked by tremors, dyskinesias, dystonic characteristics, and manifestations that improve sleep but do not include dementia. This was caused by deletions and point mutations in PARK2 (chromosome 6q25.2-27). Diminished or unusual sensations (paresthesias), loss of neuron strength both in the CNS and peripheral nerves, and lack of motor coordination are the hallmarks of neuropathy in parkinsonism. The incidence of parkinsonism during oxidative stress and ageing is associated with parkinopathy. Parkinopathy is hypothesized to be triggered by mutation of the parkin (PRKN) gene and loss of normal physiological functions of PRKN proteins, which triggers their pathogenic aggregation due to conformational changes. Two important genes that control mitochondrial health are PRKN and phosphatase and tensin homologue deleted on chromosome 10-induced putative kinase 1 (PINK1). Overexpression of TAR DNA-binding protein-43 (TDP-43) increases the aggregation of insoluble PRKN proteins in OMM. Foreign α-synuclein (ASN) promotes parkinopathy via S-nitrosylation and hence has a neurotoxic effect on dopaminergic nerves. Miro1 (Miro GTPase1), a member of the RAS superfamily, is expressed in nerve cells. Due to PINK1/PRKN and Miro1's functional relationship, an excess of mitochondrial calcium culminates in the destruction of dopaminergic neurons. An interlinked understanding of TDP-43, PINK1/PRKN, ASN, and Miro1 signalling in the communication among astrocytes, microglia, neurons, and immune cells within the brain explored the pathway of neuronal death and shed light on novel strategies for the diagnosis and treatment of parkinsonism., Competing Interests: Conflict of interest No conflict of interest between authors., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
55. Inhibitory effects of mixed flavonoid supplements on unraveled DSS-induced ulcerative colitis and arthritis.
- Author
-
Panda SP, Mahamat MSA, Rasool MA, Prasanth D, Ismail IA, Abasher MAA, and Jena BR
- Abstract
Introduction: The mixed flavonoid supplement (MFS) [Trimethoxy Flavones (TMF) + epigallocatechin-3-gallate (EGCG)] can be used to suppress inflammatory ulcers as an ethical medicine in Ayurveda. The inflammation of the rectum and anal regions is mostly attributed to nuclear factor kappa beta (NF-κB) signaling. NF-κB stimulates the expression of matrix metalloproteinase (MMP9), inflammatory cytokines tumor necrosis factor (TNF-α), and interleukin-1β (IL-1β). Although much research targeted the NF-κB and MMP9 signaling pathways, a subsequent investigation of target mediators in the inflammatory ulcer healing and NF-κB pathway has not been done. Methods: The docking studies of compounds TMF and EGCG were performed by applying PyRx and available software to understand ligand binding properties with the target proteins. The synergistic ulcer healing and anti-arthritic effects of MFS were elucidated using dextran sulfate sodium (DSS)-induced colon ulcer in Swiss albino rats. The colon mucosal injury was analyzed by colon ulcer index (CUI) and anorectic tissue microscopy. The IL-1β, tumor necrosis factor (TNF-α), and the pERK, MMP9, and NF-κB expressions in the colon tissue were determined by ELISA and Western blotting. RT-PCR determined the mRNA expression for inflammatory marker enzymes. Results: The docking studies revealed that EGCG and TMF had a good binding affinity with MMP9 (i.e., -6.8 and -6.0 Kcal/mol) and NF-kB (-9.4 and 8.3 kcal/mol). The high dose MFS better suppressed ulcerative colitis (UC) and associated arthritis with marked low-density pERK, MMP9, and NF-κB proteins. The CUI score and inflammatory mediator levels were suppressed with endogenous antioxidant levels in MFS treated rats. Conclusion: The MFS effectively unraveled anorectic tissue inflammation and associated arthritis by suppressing NF-κB-mediated MMP9 and cytokines., (© 2023 The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
56. Immunogenic Effects of Dietary Terminalia arjuna Bark Powder in Labeo rohita , a Fish Model: Elucidated by an Integrated Biomarker Response Approach.
- Author
-
Meena DK, Panda SP, Sahoo AK, Srivastava PP, Sahu NP, Kumari M, Samantaray S, Borah S, and Das BK
- Abstract
Utilizing agro-industrial waste and herbal products to create a circular bioeconomy is becoming increasingly popular. Terminalia arjuna is a significant ethnomedicinal plant that has not yet been exploited in animal feed. In the present study, nutritional Terminalia arjuna bark powder-based fish feed was created and supplied to a candidate fish species Labeo rohita at varied levels: 0% (0 g/kg), 0.5% (5 g/kg), 1% (10 g/kg), and 1.5% (15 g/kg). These treatment groups are denoted as CT, T1, T2, and T3, respectively. Utilizing a contemporary comprehensive biomarker response strategy, the study clarified the genomic influence of dietary herb inclusion. In response to bacterial infection, the immunogenic genes, STAT 1 (signal transducer and activator of transcription 1), ISG 15 (interferon stimulating gene), and Mx "myxovirus resistance gene", were shown to be elevated. The results of densitometry demonstrated a dose-dependent increase in STAT 1 and ISG 15, with Mx exhibiting maximal values at 1 g/kg TABP ( Terminalia arjuna bark powder-based feed). This is the first study to identify TABP as an immunomodulator in fish and established the IBR (Integrated Bio-marker Response) as a reliable marker in evaluating the impact of multiple drivers in a holistic manner. Thus, the present study cleared the path for TABP to be utilized as an effective feed additive which enhances the specific adaptive immune system of the fish for the production of the Green fish product for a sustainable circular bioeconomy.
- Published
- 2022
- Full Text
- View/download PDF
57. Single-cell microglial transcriptomics during demyelination defines a microglial state required for lytic carcass clearance.
- Author
-
Zia S, Hammond BP, Zirngibl M, Sizov A, Baaklini CS, Panda SP, Ho MFS, Lee KV, Mainali A, Burr MK, Williams S, Caprariello AV, Power C, Simmen T, Kerr BJ, and Plemel JR
- Subjects
- Animals, Mice, Microglia metabolism, Transcriptome, Acridine Orange adverse effects, Acridine Orange metabolism, Mice, Inbred C57BL, Disease Models, Animal, Cuprizone toxicity, Cuprizone metabolism, Demyelinating Diseases chemically induced, Demyelinating Diseases metabolism
- Abstract
Background: Microglia regulate the response to injury and disease in the brain and spinal cord. In white matter diseases microglia may cause demyelination. However, how microglia respond and regulate demyelination is not fully understood., Methods: To understand how microglia respond during demyelination, we fed mice cuprizone-a potent demyelinating agent-and assessed the dynamics of genetically fate-mapped microglia. We then used single-cell RNA sequencing to identify and track the microglial subpopulations that arise during demyelination. To understand how microglia contribute to the clearance of dead oligodendrocytes, we ablated microglia starting at the peak of cuprizone-induced cell death and used the viability dye acridine orange to monitor apoptotic and lytic cell morphologies after microglial ablation. Lastly, we treated serum-free primary microglial cultures to model distinct aspects of cuprizone-induced demyelination and assessed the response., Results: The cuprizone diet generated a robust microglial response by week 4 of the diet. Single-cell RNA sequencing at this time point revealed the presence of several cuprizone-associated microglia (CAM) clusters. These clusters expressed a transcriptomic signature indicative of cytokine regulation and reactive oxygen species production with altered lysosomal and metabolic changes consistent with ongoing phagocytosis. Using acridine orange to monitor apoptotic and lytic cell death after microglial ablation, we found that microglia preferentially phagocytose lytic carcasses. In culture, microglia exposed to lytic carcasses partially recapitulated the CAM state, suggesting that phagocytosis contributes to this distinct microglial state during cuprizone demyelination., Conclusions: Microglia serve multiple roles during demyelination, yet their transcriptomic state resembles other neurodegenerative conditions. The phagocytosis of cellular debris is likely a universal cause for a common neurodegenerative microglial state., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
58. Molecular Mechanism and Role of Japanese Encephalitis Virus Infection in Central Nervous System-Mediated Diseases.
- Author
-
Yadav P, Chakraborty P, Jha NK, Dewanjee S, Jha AK, Panda SP, Mishra PC, Dey A, and Jha SK
- Subjects
- Humans, Endothelial Cells metabolism, Endoplasmic Reticulum Chaperone BiP, Dopamine, Central Nervous System, Receptors, Cell Surface, Lectins, C-Type metabolism, Encephalitis Virus, Japanese physiology, Neurodegenerative Diseases pathology, Encephalitis, Japanese, Encephalitis Viruses, Japanese metabolism
- Abstract
The Japanese encephalitis virus (JEV) is the most common cause of neurodegenerative disease in Southeast Asia and the Western Pacific region; approximately 1.15 billion people are at risk, and thousands suffer from permanent neurological disorders across Asian countries, with 10-15 thousand people dying each year. JEV crosses the blood-brain barrier (BBB) and forms a complex with receptors on the surface of neurons. GRP78, Src, TLR7, caveolin-1, and dopamine receptor D2 are involved in JEV binding and entry into the neurons, and these receptors also play a role in carcinogenic activity in cells. JEV binds to GRP78, a member of the HSP70 overexpressed on malignant cells to enter neurons, indicating a higher chance of JEV infection in cancer patients. However, JEV enters human brain microvascular endothelial cells via an endocytic pathway mediated by caveolae and the ezrin protein and also targets dopamine-rich areas for infection of the midbrain via altering dopamine levels. In addition, JEV complexed with CLEC5A receptor of macrophage cells is involved in the breakdown of the BBB and central nervous system (CNS) inflammation. CLEC5A-mediated infection is also responsible for the influx of cytokines into the CNS. In this review, we discuss the neuronal and macrophage surface receptors involved in neuronal death.
- Published
- 2022
- Full Text
- View/download PDF
59. Co-Prevalence of Virulence and Pathogenic Potential in Multiple Antibiotic Resistant Aeromonas spp. from Diseased Fishes with In Silico Insight on the Virulent Protein Network.
- Author
-
Chakraborty N, Das BK, Bera AK, Borah S, Mohanty D, Yadav AK, Kumar J, Koushlesh SK, Chanu TN, Panda SP, and Vallangi R
- Abstract
Aeromonas species exhibit widespread presence in food, poultry, and aquaculture. They are major multi-drug-resistant fish pathogens. This study aims to identify Aeromonas species harbouring virulence genes aerolysin, flagellin, and lipase from diseased fishes of Assam wetlands with association with antibiotic resistance and in vivo pathogenicity. One hundred and thirty-four Aeromonas strains were isolated and thirty representative species identified using genus-specific 16S rRNA gene amplification. A. veronii was most prevalent (53.7%) followed by A. hydrophila (40.2%), A. caviae (4.47%), and A. dhakensis (1.49%). Ninety percent (90%) of strains harboured at least one of the studied virulence genes: aerA (73.3%), lip (46.6%), and flaA (26.6%). The highest multiple antibiotic resistance (MAR) index 0.8 corresponded to A. hydrophila DBTNE1 (MZ723069), containing all the studied genes. The lowest LD50 values (1.6 × 106 CFU/fish) corresponded to isolates having both aerA and lip. β-lactams showed utmost resistance and lowest for aminoglycosides. There was a significant (p < 0.05) Pearson chi-square test of association between the occurrence of virulence and antibiotic resistance. The in silico protein−protein interaction revealed important drug targets, such as σ28 transcription factor, aminoacyl-tRNA synthetase, and diacylglycerol kinase, with significant (p < 0.05) enrichment. This study suggests that fish-isolate Aeromonas strains represent potential threat to aquaculture with subsequent risk of transferring antibiotic resistance to human pathogens.
- Published
- 2022
- Full Text
- View/download PDF
60. The interplay of epilepsy with impaired mitophagy and autophagy linked dementia (MAD): A review of therapeutic approaches.
- Author
-
Panda SP, Dhurandhar Y, and Agrawal M
- Subjects
- Anticonvulsants therapeutic use, Carbamazepine adverse effects, Felbamate therapeutic use, Gabapentin therapeutic use, Humans, Inflammasomes, Lamotrigine therapeutic use, Mitophagy, NF-kappa B, NLR Family, Pyrin Domain-Containing 3 Protein, Oxcarbazepine therapeutic use, Phenytoin therapeutic use, Seizures, Topiramate therapeutic use, Triazines adverse effects, Ubiquitin-Protein Ligases, Valproic Acid therapeutic use, Dementia chemically induced, Dementia complications, Dementia drug therapy, Epilepsy complications, Epilepsy drug therapy, Parkinson Disease
- Abstract
The duration and, age of dementia have been linked to a higher risk of seizures. The exact mechanism that drives epileptogenesis in impaired mitophagy and autophagy linked dementia (MAD) is fully defined after reviewing the Scopus, Publon, and Pubmed databases. The epileptogenesis in patients with Alzheimer's disease dementia (ADD) and Parkinson's disease dementia (PDD) is due to involvement of amyloid plaques (Aβ), phosphorylated tau (pTau), Parkin, NF-kB and NLRP3 inflammasome. Microglia, the prime protective and inflammatory cells in the brain exert crosstalk between mitophagy and inflammation. Several researchers believed that the inflammatory brain cells microglia could be a therapeutic target for the treatment of a MAD associated epilepsy. There are conventional antiepileptic drugs such as gabapentin, lamotrigine, phenytoin sodium, carbamazepine, oxcarbazepine, felbamate, lamotrigine, valproate sodium, and topiramate are prescribed by a psychiatrist to suppress seizure frequency. Also, the conventional drugs generate serious adverse effects and synergises dementia characteristics. The adverse effect of carbamazepine is neurotoxic and also, damages haemopoietic system and respiratory tract. The phenytoin treatment causes cerebellar defect and anemia. Dementia and epilepsy have a complicated relationship, thus targeting mitophagy for cure of epileptic dementia makes sense. Complementary and alternative medicine (CAM) is one of the rising strategies by many patients of the world, not only to suppress seizure frequency but also to mitigate dementia characteristics of patients. Therefore our present review focus on the interplay between epilepsy and MAD and their treatment with CAM approaches., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. and Mitochondria Research Society. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
61. A review of dementia, focusing on the distinct roles of viral protein corona and MMP9 in dementia: Potential pharmacotherapeutic priorities.
- Author
-
Panda SP and Soni U
- Subjects
- Amyloid beta-Peptides metabolism, Humans, Neurofibrillary Tangles pathology, Viral Proteins, tau Proteins metabolism, Alzheimer Disease metabolism, Dementia diagnosis, Matrix Metalloproteinase 9 metabolism, Parkinson Disease pathology, Protein Corona
- Abstract
Dementia, in particular, is a defining feature of Alzheimer's and Parkinson's diseases. Because of the combination of motor and cognitive impairments, Parkinson's disease dementia (PDD) has a greater impact on affected people than Alzheimer's disease dementia (ADD) and others. If one family member develops dementia, the other members will suffer greatly in terms of social and occupational functioning. Currently, no relevant treatment is available based on an examination of the absolute pathophysiology of dementia. As a result, our objective of current review encouraged to look for dementia pharmacotherapy based on their pathogenesis. We systematically searched electronic databases such as PubMed, Scopus, and ESCI for information on the pathophysiology of demetia, as well as their treatment with allopathic and herbal medications. By modulating intermediate proteins, oxidative stress, viral protein corona, and MMP9 are etiological factors that cause dementia. The pathophysiology of ADD was described by two hypotheses: the amyloid cascade hypothesis and the tau and tangle hypothesis. ADD is caused by an increase in amyloid-beta (Aβ) and neurofibrillary tangles in the cerebrum. The viral protein corona (VPC) is more contagious and helps to form amyloid-beta (Aβ) plaques and neurofibrillary tangles in the cerebrum. Thioredoxin interacting protein (TXNIP) inside the BBB encourages Aβ to become more engaged. PDD is caused by decreased or absent dopamine secretion from nerve cells in the substantia nigra, as well as PRKN gene deletion/duplication mutations, and shift in the PRKN-PACRG organisation, all of which are linked to ageing. This article discussed the pathophysiology of dementia, as well as a list of herbal medications that can easily cross the BBB and have a therapeutic effect on dementia., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
62. AQbD Driven Development of an RP-HPLC Method for the Quantitation of Abiraterone Acetate for its Pharmaceutical Formulations in the Presence of Degradants.
- Author
-
Jena BR, Panda SP, Kulandaivelu U, Alavala RR, Rao GSNK, Swain S, Pattnaik G, and Ghose D
- Abstract
Objectives: Abiraterone acetate is a well-known anticancer drug and a steroidal derivative of progesterone for treatment of patients with hormone-refractory prostate cancer. Chemometrics-assisted reverse phase high performance liquid chromatography (RP-HPLC) development of the drug abiraterone acetate has been employed in this study using an analytical quality by design (AQbD) approach., Materials and Methods: Drug separation was performed using a Princeton Merck-Hibar Purospher STAR (C18, 250 mm × 4.6 mm) i.d., 5 μm particle size) with ultraviolet detection at 235 nm. A Box-Behnken statistical experimental design with response surface methodology was executed for method optimization and desired chromatographic separation from its formulation with a few numbers of experimental trials. The impact of three independent variables, namely, composition of the mobile phase, pH, and flow rate, on response retention time and peak area was studied by constructing an arithmetic model from these variables., Results: Optimized experimental conditions for the proposed work include the mobile phase acetonitrile and phosphate buffer (10 mM KH
2 PO4 ) (20:80 %v/v). At the concentration range of 2-100 μg/mL, a linear calibration curve was found. Recovery was performed at three concentrations and was foun to be between 98% and 102%. The 3D response surface curves revealed that mobile phase composition and flow rate were the most substantial critical factors affecting desired responses., Conclusion: An attempt has been made to develop and validate an economical, precise, robust, stability-indicating AQbD-based RP-HPLC method that can be employed successfully for the routine analysis of abiraterone acetate in quality control labs.- Published
- 2021
- Full Text
- View/download PDF
63. An organophotoredox-catalyzed redox-neutral cascade involving N -(acyloxy)phthalimides and allenamides: synthesis of indoles.
- Author
-
Das S, Azim A, Hota SK, Panda SP, Murarka S, and De Sarkar S
- Abstract
An organophotoredox-catalyzed radical cascade of allenamides and alkyl N -(acyloxy)phthalimides for the synthesis of indoles is documented. The method features mild and robust reaction conditions, and exhibits broad scope. The tandem process enriches the limited repertoire of alkyl NHPI ester addition on electron-rich π-bonds as well as radical chemistry involving allenamides.
- Published
- 2021
- Full Text
- View/download PDF
64. In silico identification of potential inhibitors from Cinnamon against main protease and spike glycoprotein of SARS CoV-2.
- Author
-
Prasanth DSNBK, Murahari M, Chandramohan V, Panda SP, Atmakuri LR, and Guntupalli C
- Subjects
- COVID-19, Computer Simulation, Humans, Molecular Docking Simulation, Cinnamomum zeylanicum chemistry, Coronavirus 3C Proteases antagonists & inhibitors, Protease Inhibitors pharmacology, SARS-CoV-2 drug effects, Spike Glycoprotein, Coronavirus antagonists & inhibitors
- Abstract
Cinnamon has been utilized to remedy a lot of afflictions of humans. Literary works illustrate that it possesses numerous biological activities. Our research study is intended to recognize the phyto-derived antiviral substances from Cinnamon against COVID-19 main protease enzyme and to understand the in silico molecular basis of its activity. In the present study, 48 isolates compounds from Cinnamon retrieved from the PubMed database, are subjected to docking analysis. Docking study was performed using Autodock vina and PyRx software. Afterwards, admetSAR, as well as DruLiTo servers, were used to investigate drug-likeness prophecy. Our study shows that the nine phytochemicals of Cinnamon are very likely against the main protease enzyme of COVID-19. Further MD simulations could identify Tenufolin (TEN) and Pavetannin C1 (PAV) as hit compounds. Utilizing contemporary strategies, these phyto-compounds from a natural origin might establish a reliable medication or support lead identification. Identified hit compounds can be further taken for in vitro and in vivo studies to examine their effectiveness versus COVID-19.
- Published
- 2021
- Full Text
- View/download PDF
65. A Selective and Sensitive Method Development and Validation of 1,1-Dimethyl-3-Hydroxy-Pyrrolidinium Bromide Impurity in Glycopyrrolate Oral Solution by Liquid Chromatography-Tandem Mass Spectroscopy.
- Author
-
Chawla RK, Rao GSNK, Kulandaivelu U, Panda SP, and Alavala RR
- Subjects
- Chromatography, Liquid methods, Limit of Detection, Bromides analysis, Drug Contamination, Glycopyrrolate chemistry, Muscarinic Antagonists chemistry, Tandem Mass Spectrometry methods
- Abstract
Objective: A selective and sensitive liquid chromatography-tandem mass spectrometer (LC-MS/MS) method has been developed for the quantification of 1,1-dimethyl-3-hydroxy-pyrrolidinium bromide impurity in glycopyrrolate oral solution., Materials and Method: The LC-MS/MS analysis was done on X Bridge HILIC (100 × 4.6 mm, 5 μm) analytical column, and the mobile phase used was10 mM ammonium formate with 0.2% formic acid as mobile phase-A and acetonitrile as mobile phase-B with a gradient programme of 5.0 min. The flow rate used was 1.2 mL/min. Triple quadrupole mass detector coupled to positive electrospray ionization operated in multiple reactions monitoring mode was used for the quantification at m/z 116.10 ± 0.5., Results: Retention time of impurity was found ~3.2 min. The method was validated in terms of specificity, linearity, accuracy, precision, range, limit of detection, limit of quantitation (LOQ) and robustness. Relative standard deviation (RSD) for system suitability was found 1.3%. Calibration plot was linear over the range of 0.050-2.000 μg/mL. Limit of detection and limit of quantification were found 0.017 and 0.051 μg/mL, respectively. The intra- and inter-day precision RSD was 2.3% and the obtained recovery at LOQ to 200% was in between 86.7 and 107.4%., Conclusion: The low RSD values and high recoveries of the method confirm the suitability of the method., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2021
- Full Text
- View/download PDF
66. Evidence of Transmission of Goatpox between Domestic Goats and Wild Himalayan Goral (Naemorhedus goral) in Arunachal Pradesh, India.
- Author
-
Bora DP, Ahmed J, Tadap S, Pariat AO, Mech P, Panda SP, Tashi T, Kakati P, Ingtipi S, Qayum A, Dutta LJ, and Barman NN
- Subjects
- Animals, Animals, Wild, Disease Outbreaks veterinary, India epidemiology, Phylogeny, Poxviridae Infections virology, Capripoxvirus genetics, Goat Diseases virology, Goats virology, Poxviridae Infections veterinary, Ruminants virology
- Abstract
Examination of carcasses of Himalayan goral (Naemorhedus goral) revealed nodular, pox-like eruptions in the skin. Similar disease was also seen in domestic goats (Capra aegagrus hircus) in the same area. Goatpox virus was identified as the etiology of the disease in both cases, with probable transmission between the species., (© Wildlife Disease Association 2021.)
- Published
- 2021
- Full Text
- View/download PDF
67. Lead Finding from Selected Flavonoids with Antiviral (SARS-CoV-2) Potentials Against COVID-19: An In-silico Evaluation.
- Author
-
Gorla US, Rao K, Kulandaivelu US, Alavala RR, and Panda SP
- Subjects
- Angiotensin-Converting Enzyme 2 chemistry, Angiotensin-Converting Enzyme 2 metabolism, Animals, Antiviral Agents chemistry, Antiviral Agents toxicity, Binding Sites, Computer Simulation, Flavonoids chemistry, Flavonoids toxicity, Molecular Docking Simulation, Protein Domains, Rats, Spike Glycoprotein, Coronavirus chemistry, Spike Glycoprotein, Coronavirus metabolism, Antiviral Agents pharmacology, Drug Evaluation, Preclinical methods, Flavonoids pharmacology, SARS-CoV-2 drug effects
- Abstract
Background: COVID-19 is a pandemic respiratory contagious viral (SARS-CoV-2) disease associated with high morbidity and mortality worldwide. Currently, there are no effective preventive or treatment strategies for COVID-19 and it has been declared as a global health emergency by WHO. In silico molecular docking studies can be useful to predict the binding affinity between the phytocompound and the target protein and play a vital role in finding an inhibitor through structure-based drug design., Objective: In this aspect, our objective was to screen essential flavonoids against possible protein targets such as SARS-CoV-2 spike glycoprotein receptor binding domain (RBD-S) and host Angiotensin Converting Enzyme-2 protease domain (PD-ACE-2) using in silico molecular docking studies., Methods: Approximately 49 flavonoids were identified and were evaluated for their drug-likeness based on Lipinski rule, bioactivity scores, antiviral and toxicity profiles using SwissADME, Molinspiration, PASS and GUSAR online tools. The flavonoids that passed Lipinski rule were subjected to in silico analysis through molecular docking on RBD-S and PD-ACE-2 using Molegro Virtual Docker v6.0., Results: The bioactive flavonoids that showed NIL violations and were found in compliance with Lipinski rule were selected for docking studies. In silico analysis reported that biochanin A and silymarin bind significantly at the active sites of RBD-S and PD-ACE-2 with a MolDock score of -78.41and -121.28 kcal/mol respectively. Bioactivity scores, antiviral potential and toxicity profiles were predicted for the top interacting phytocompounds and substantial relevant data was reported., Conclusion: The current outcomes created a new paradigm for understanding biochanin A and silymarin bioflavonoids as potent inhibitors of RBD-S and PD-ACE-2 targets respectively. Further work can be extended to confirm their therapeutic potential for COVID-19., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)
- Published
- 2021
- Full Text
- View/download PDF
68. A trimethoxy flavonoid isolated from stem extract of Tabebuia chrysantha suppresses angiogenesis in angiosarcoma.
- Author
-
Panda SP, Panigrahy UP, Prasanth D, Gorla US, Guntupalli C, Panda DP, and Jena BR
- Subjects
- Animals, Cell Proliferation drug effects, Chick Embryo, Chorioallantoic Membrane, Flavonoids pharmacology, Plant Extracts pharmacology, Signal Transduction drug effects, Xenograft Model Antitumor Assays, Angiogenesis Inhibitors pharmacology, Hemangiosarcoma drug therapy, Matrix Metalloproteinase 9 metabolism, STAT3 Transcription Factor metabolism, Tabebuia
- Abstract
Objectives: This research aimed to evaluate the antiangiogenic activity of isolated flavonoid 4a,5,8,8a-tetrahydro-5-hydroxy-3,7,8-trimethoxy-2-(3,4-dimethoxyphenyl) chromen-4-one (TMF) from Tabebuia chrysantha. STAT3-MMP9 signalling is a signal transduction mechanism that promotes angiogenesis in various cancers., Methods: The tumour xenografting chicken embryo chorioallantoic membrane (CAM) model-based ex vivo assay was used to evaluate the activity of TMF. The Western blot, densitometric analysis and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to evaluate the activity of the MMP9. Zebrafish embryos were used to evaluate embryotoxicity, and in vitro free radical scavenging activity of flavonoid was also elucidated., Key Findings: This research assessed the high level of STAT3, p-ERK, VEGF-R and MMP9 in the tissue extract of the control group, and also, the suppression of angiogenesis in the treatment groups was due to scavenged ROS and RNS, dephosphorylation of STAT3 and ERK, and suppression of MMP9 gene expression., Conclusion: The isolated flavonoid named TMF from T. chrysantha functions as specific regulators of target proteins of angiosarcoma. The STAT3-MMP9 signalling may be used as an effective prognostic marker of angiosarcoma., (© 2020 Royal Pharmaceutical Society.)
- Published
- 2020
- Full Text
- View/download PDF
69. Molecular characterization, constitutive expression and GTP binding mechanism of Cirrhinus mrigala (Hamilton, 1822) Myxovirus resistance (Mx) protein.
- Author
-
Roy P, Rout AK, Maharana J, Sahoo DR, Panda SP, Pal A, Nayak KK, Behera BK, and Das BK
- Subjects
- Amino Acid Sequence, Animals, Cloning, Molecular, DNA, Complementary genetics, Fish Proteins chemistry, Kinetics, Molecular Dynamics Simulation, Myxovirus Resistance Proteins chemistry, Phylogeny, Protein Binding, Protein Domains, Protein Stability, RNA, Messenger genetics, Thermodynamics, Cypriniformes genetics, Fish Proteins genetics, Fish Proteins metabolism, Gene Expression Regulation, Guanosine Triphosphate metabolism, Myxovirus Resistance Proteins genetics, Myxovirus Resistance Proteins metabolism
- Abstract
Myxovirus resistance (Mx) proteins represents the subclass of the dynamin superfamily of large Guanosine triphosphates (GTPases), play esential role in intracellular vesicle trafficking, endocytosis, organelle homeostasis and mitochondria distribution. These proteins are key players of the vertebrate immune system, induced by type-I and type-III interferons (IFN) of infected host and inhibit viral replication by sequestering its nucleoprotein. In the present study, we report the sequencing and characterization of Cirrhinus mrigala Mx protein (CmMx) for the first time and observed its constitutive expression in different tissues for a period of fourteen days. The synthetic peptide, LSGVALPRGTGI, was dissolved in PBS and injected into a rabbit and the antibody raised against CmMx was used to study the level of its expression. The full length of the CmMx cDNA is 2244 bp with a molecular mass of 70.9 kDa and a predicted isoelectric point of 8.25. The 627 amino acids polypeptide formed of three main functional domains: N-terminal GTPase domain (GD), a middle domain (MD) and GTPase effector domain (GED) with carboxy terminal leucine zipper motif. The 3D models of CmMx protein was modeled based on available close structural homologs and further validated through molecular dynamics (MD) simulations. MD study revealed the importance of G-domain responsible for recognition of GTP, which perfectly corroborate with earlier studies. MM/PBSA binding free energy analysis displayed that van der Waals and electrostatic energy were the key driving force behind molecular recognition of GTP by CmMx protein. The results from this study will illuminate more lights into the ongoing research on myxovirus resistance protein and its role in inhibition of viral replication in other eukaryotic system as well., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
70. Stem extract of Tabebuia chrysantha induces apoptosis by targeting sEGFR in Ehrlich Ascites Carcinoma.
- Author
-
Panda SP, Panigrahy UP, Panda S, and Jena BR
- Subjects
- Animals, Antineoplastic Agents, Phytogenic administration & dosage, Antineoplastic Agents, Phytogenic isolation & purification, Antioxidants administration & dosage, Antioxidants isolation & purification, Antioxidants pharmacology, Apoptosis drug effects, Artemia drug effects, Carcinoma, Ehrlich Tumor pathology, Chromatography, High Pressure Liquid methods, Dose-Response Relationship, Drug, ErbB Receptors antagonists & inhibitors, ErbB Receptors metabolism, Female, Male, Mice, Plant Extracts administration & dosage, Plant Stems, Antineoplastic Agents, Phytogenic pharmacology, Carcinoma, Ehrlich Tumor drug therapy, Plant Extracts pharmacology, Tabebuia chemistry
- Abstract
Ethnopharmacological Relevance: The plant Tabebuia chrysantha (Jaq.) Nicholson (Bignoniaceae) is commonly known as "Golden Goddess" in the Southern part of India and "Golden Trumpet Tree " in Central America. Stems of this plant have been traditionally used for antioxidant, anti-inflammatory, antimicrobial and anticancer actions., Aim of the Study: To evaluate the antitumor activity of methanol extract of Tabebuia chrysantha stem (METC)., Materials and Methods: The in vivo antitumor potential of METC against Ehrlich Ascites Carcinoma (EAC) in Swiss albino mice was assessed by evaluating tumor volume, viable and nonviable tumor cell count, tumor weight, hematological parameters, biochemical parameters, and antioxidant parameters. The in vitro antitumor potential of METC at different concentrations (100, 200, 400, 800, 1000) µg/mL has been evaluated, by using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and Trypan blue dilution assay for a period of 3 h treatment. Before that, the crude extract was pre-screened for cytotoxicity property using Brine shrimp lethality bioassay., Results: Phytoconstituents 2-Hydroxynaphthalene-1,4-dione, β-lapachone and 2-((dimethylamino)methyl)-3-methoxynaphthalene-1,4-dione were isolated from the METC. Their occurrence and structures were determined by HPLC chromatography, UV spectroscopy, and 1D and
2 D NMR spectroscopies respectively. The extract showed a direct cytotoxic effect on EAC cells in a dose-dependent manner with IG50 value 463.27 µg/mL in MTT assay and 443.58 µg/mL in trypan blue dilution assay. The METC (300 mg/kg) and 5-FU (30 mg/kg) exhibited significant (p < 0.001) decrease in tumor volume, tumor weight and viable cell count of EAC-treated mice. Also, hematological profile, tissue parameters such as lipid peroxidation, reduced glutathione, superoxide dismutase, and catalase were reverted to the normal levels compared to the EAC control group. The Western blotting analysis demonstrated apoptosis of carcinoma was due to inhibition of soluble epidermal growth factor receptor proteins (sEGFR) expression in the blood., Conclusion: The antitumor potential of the stem extract of T chrysantha was due to naphthaquinones and polyphenol content in the crude extract and so T chrysantha could be a cytotoxic plant to control tumor growth., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
71. Molecular cloning, GTP recognition mechanism and tissue-specific expression profiling of myxovirus resistance (Mx) protein in Labeo rohita (Hamilton) after Poly I:C induction.
- Author
-
Das BK, Roy P, Rout AK, Sahoo DR, Panda SP, Pattanaik S, Dehury B, Behera BK, and Mishra SS
- Subjects
- Animals, Cloning, Molecular methods, Cyprinidae virology, Female, GTP Phosphohydrolases metabolism, Male, Myxovirus Resistance Proteins genetics, Orthomyxoviridae, Ovum metabolism, Phylogeny, Protein Domains, Real-Time Polymerase Chain Reaction, Sequence Analysis, DNA, Tissue Distribution, Transcriptome drug effects, Cyprinidae metabolism, Guanosine Triphosphate metabolism, Myxovirus Resistance Proteins metabolism, Poly I-C pharmacology
- Abstract
The myxovirus resistance (Mx) proteins belong to interferon-induced dynamin GTPase and play pivotal role in the inhibition of replication of numerous viruses. These antiviral proteins are released in usual or diseased condition to prevent the viral attack and to carry regular cellular activities like endocytosis and trafficking of nucleoproteins into the nucleus. The invasion of virus up-regulates the expression of Mx transcripts and double-stranded RNA mimic like polyinosinic polycytidyilic acid (Poly I:C). To understand the tissue-specific expression profiling and mechanism of GTP recognition of Mx protein from Labeo rohita (rohu), the full-length gene was cloned, sequenced and characterized through various Bioinformatics tools for the first time. The Mx cDNA was comprised of 2297 bp, and the open reading frame of 1938 bp encodes polypeptide of 631 amino acids. The coding sequence of Mx protein possess the signature motif of dynamin superfamily, LPRG(S/K)GIVTR, the tripartite guanosine-5/triphosphate (GTP)-binding motif (GXXXSGKS/T, DXXG and T/NKXD) and the leucine zipper motifs at the C-terminal end, well conserved in all interferon-induced Mx protein in vertebrates. Western blotting confirmed the molecular weight of Mx protein to be 72 kDa. After the intraperitoneal challenge of L. rohita with a Poly I:C, up-regulation of Mx protein was observed in brain, spleen, liver, kidney, intestine, heart, muscle, and gill. Ontogeny study displayed pronounced expression of Mx protein in all stages of the developmental of Rohu after Poly I:C induction. However a persistent expression of Mx transcript was also observed in Rohu egg as well as milt without induction with Poly I:C. Higher expression of Mx gene was observed on 96 h where it was 6.4 folds higher than the control. The computational modelling of Mx protein portrayed the tripartite N-terminal G-domain that binds to GTP, the bundle-signaling element (BSE) which interconnects the G-domain to the elongated stalk domain and C-terminal helical stalk domain. In agreement with the experimental studies, a series of conserved residues viz., Gln52, Ser53, Ser54, Leu68, Pro69, Gly71, Gly73, Thr76, Asp151, Gly154, Thr220, Lys221, Val251, Cys253, Arg254, and Gly255 were computed to be indispensable for tight anchoring of GTP within binding cavity of G-domain. The binding free energy calculation study depicted that the van der Waals and electrostatic terms contributs significantly to molecular recognition of GTP. Collectively, our study provides mechanistic insights into the tissue-specific expression profiling and GTP binding mechanism of Mx protein from Labeo rohita, which is expected to drive further research on several cellular events including viral resistance and endocytosis in the near future.
- Published
- 2019
- Full Text
- View/download PDF
72. Absolute Abstinence as a Treatment Outcome in Servicemen with Alcohol Dependence: A Retrospective Cohort Study.
- Author
-
Ratnam A, Das RC, Madhusudan T, Sharma P, and Panda SP
- Subjects
- Adult, Alcoholism psychology, Goals, Humans, India, Male, Middle Aged, Military Personnel, Recurrence, Retrospective Studies, Treatment Outcome, Adaptation, Psychological physiology, Alcohol Abstinence psychology, Alcoholism therapy
- Abstract
Background : Within India's military medical framework, alcohol dependence syndrome (ADS) is deemed a treatable medical illness incompatible with military service, and complete abstinence is the only acceptable successful treatment outcome. Objective : This study was designed to identify factors which were able to differentiate treatment outcomes of abstinence and relapse among ADS patients in a military framework. Method : Recognizing personal incentives to misrepresent alcohol consumption, abstinence, and relapse outcomes were established using official reports from a patient's parent unit, in combination with biochemical parameters and clinical examination. Patients serially admitted for ADS treatment or follow-up review were surveyed, and their socio-demographic and alcohol consumption profiles, coping styles, life events and specific relapse precipitants were recorded and compared as contributory variables in a cognitive-behavioral model of ADS. From this survey of 140 patients, membership to abstainer or relapser groups was then predicted using a discriminant analysis. Results : 34% of patients achieved early absolute abstinence. No baseline socio-demographic or drinking profile distinctions existed between abstainers and relapsers. Differences were forthcoming on coping styles, life-event, and relapse-precipitant exposure measures. Stepwise discriminant analysis produced a final equation comprising 10 independent variables (including two positive life event measures), which predicted an abstinence/relapse outcome with an 86% and 79% hit-rate (original and cross-validated). Conclusion : Using prevailing cognitive-behavioral constructs, early absolute abstinence emerged as an actionable objective and an achievable goal without any contributory socio-demographic predilections. This preliminary evaluation suggests it is a tenable and realistic target of current ADS treatment programs.
- Published
- 2019
- Full Text
- View/download PDF
73. Psychiatric comorbidity in multiple sclerosis.
- Author
-
Panda SP, Das RC, Srivastava K, Ratnam A, and Sharma N
- Subjects
- Comorbidity, Depression, Disability Evaluation, Humans, Male, Psychiatric Status Rating Scales, Quality of Life, Multiple Sclerosis
- Abstract
Aim: To study the prevalence of psychiatric comorbidities in patients of multiple sclerosis and their association to the degree of disability., Method: Psychiatric symptoms were assessed in 90 patients of multiple sclerosis using GHQ-12, MMSE, HADS, Beck Depression Inventory and AUDIT. Neurological disability was assessed using Expanded Disability Status Scale. Correlations were determined between EDSS scores and psychiatric scale scores., Result: 61% of patients had significant psychological distress. Depression was most common (38.8%) which was followed by anxiety symptoms (27.8%). Cognitive functioning was relatively intact in patients with mild to moderate neurological disability. Alcohol abuse was mostly restricted to male gender., Conclusion: Psychiatric illness is highly prevalent in patients of multiple sclerosis leading to poor quality of life and significant distress. Psychiatric disability was higher in patients who had greater deterioration in neurological function. All cases of MS should be assessed for psychiatric morbidities as can be alleviated by appropriate intervention., (Copyright © 2018 Polish Neurological Society. Published by Elsevier Sp. z o.o. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
74. Diagnosis and Management of Rhabdomyosarcoma in Children and Adolescents: ICMR Consensus Document.
- Author
-
Panda SP, Chinnaswamy G, Vora T, Prasad M, Bansal D, Kapoor G, Radhakrishnan V, Agarwala S, Laskar S, Arora B, Kaur T, Rath GK, and Bakhshi S
- Subjects
- Adolescent, Child, Humans, India, Rhabdomyosarcoma pathology, Rhabdomyosarcoma therapy, Soft Tissue Neoplasms pathology, Soft Tissue Neoplasms therapy, Rhabdomyosarcoma diagnosis, Soft Tissue Neoplasms diagnosis
- Abstract
Rhabdomyosarcoma (RMS) is a highly malignant tumor which is thought to originate from the pluripotent mesenchyme. It is the most common soft-tissue sarcoma of childhood. This review article summarizes the recent and older published literature and gives an overview of management of RMS in children. RMS can arise in a wide variety of primary sites, some of which are associated with specific patterns of local invasion, regional lymph nodal spread, therapeutic response and long term outcome, hence requiring physicians to be familiar with site-specific staging and treatment details. Most common primary sites include the head and neck region, genitourinary tract, and extremities. Prognosis for children and adolescents with RMS has recently improved substantially, especially for patients with local or locally extensive disease because of the development of multi-modal therapy incorporating surgery, dose-intensive combination chemotherapy, and radiation therapy. Despite aggressive approaches the outcome for patients who present with metastatic disease remains unsatisfactory. Clinical trials are ongoing to reduce toxicity and improve outcomes of such patients; newer agents in combination are being investigated.
- Published
- 2017
- Full Text
- View/download PDF
75. Instability of the Human Cytochrome P450 Reductase A287P Variant Is the Major Contributor to Its Antley-Bixler Syndrome-like Phenotype.
- Author
-
McCammon KM, Panda SP, Xia C, Kim JJ, Moutinho D, Kranendonk M, Auchus RJ, Lafer EM, Ghosh D, Martasek P, Kar R, Masters BS, and Roman LJ
- Subjects
- Amino Acid Substitution, Crystallography, X-Ray, Cytochrome P-450 Enzyme System metabolism, Enzyme Stability genetics, Humans, Antley-Bixler Syndrome Phenotype enzymology, Antley-Bixler Syndrome Phenotype genetics, Cytochrome P-450 Enzyme System chemistry, Cytochrome P-450 Enzyme System genetics, Mutation, Missense
- Abstract
Human NADPH-cytochrome P450 oxidoreductase (POR) gene mutations are associated with severe skeletal deformities and disordered steroidogenesis. The human POR mutation A287P presents with disordered sexual development and skeletal malformations. Difficult recombinant expression and purification of this POR mutant suggested that the protein was less stable than WT. The activities of cytochrome P450 17A1, 19A1, and 21A2, critical in steroidogenesis, were similar using our purified, full-length, unmodified A287P or WT POR, as were those of several xenobiotic-metabolizing cytochromes P450, indicating that the A287P protein is functionally competent in vitro, despite its functionally deficient phenotypic behavior in vivo Differential scanning calorimetry and limited trypsinolysis studies revealed a relatively unstable A287P compared with WT protein, leading to the hypothesis that the syndrome observed in vivo results from altered POR protein stability. The crystal structures of the soluble domains of WT and A287P reveal only subtle differences between them, but these differences are consistent with the differential scanning calorimetry results as well as the differential susceptibility of A287P and WT observed with trypsinolysis. The relative in vivo stabilities of WT and A287P proteins were also examined in an osteoblast cell line by treatment with cycloheximide, a protein synthesis inhibitor, showing that the level of A287P protein post-inhibition is lower than WT and suggesting that A287P may be degraded at a higher rate. Current studies demonstrate that, unlike previously described mutations, A287P causes POR deficiency disorder due to conformational instability leading to proteolytic susceptibility in vivo, rather than through an inherent flavin-binding defect., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)
- Published
- 2016
- Full Text
- View/download PDF
76. Expression of Mx Gene in Cirrhinus mrigala (Hamilton, 1822) to OmpC Protein of Aeromonas hydrophila and Bacterial Infection.
- Author
-
Roy P, Panda SP, Pal A, Mishra SS, Jayasankar P, and Das BK
- Subjects
- Animals, Electrophoresis, Agar Gel, Kinetics, RNA, Messenger genetics, Aeromonas hydrophila metabolism, Cyprinidae genetics, Gram-Negative Bacterial Infections genetics, Porins administration & dosage
- Abstract
The aims of this study were to identify alternative myxovirus (Mx) stimulatory compounds in Cirrhinus mrigala and to characterize the kinetics and intensity of their stimulated responses by semi-quantitative RT-PCR. Mx transcripts were measured in C. mrigala injected with Aeromonas OmpC (outer membrane protein) at a dose 0.4 mg/fish. At day 1, day 2, day 3, day 5, day 10, day 20 and day 30, samples were collected from kidney, spleen, liver, heart brain, gill, intestine and muscle for the study of Mx transcript and housekeeping gene β-actin. Similarly, Mx gene expression was also studied in Aeromonas hydrophila-infected fish for a period of 10 days. Mx/β-actin ratio was constitutively expressed from all the organs of OmpC-vaccinated fish. The expression was significantly highest (P ≤ 0.05) in spleen, followed by liver, kidney, intestine, gill, heart, muscle and brain. The expression was highest in day 2 except spleen (on day 3) and subsequently reduced up to day 30. Control fish also showed Mx expression. Similarly, A. hydrophila-infected fish showed Mx/β-actin ratio upregulated significantly in the spleen and kidney on day 5, liver on day 2 and intestine on day 3. This study revealed that OmpC of A. hydrophila and its infection could stimulate the antiviral Mx gene of C. mrigala.
- Published
- 2016
- Full Text
- View/download PDF
77. Construction, De-Novo Assembly and Analysis of Transcriptome for Identification of Reproduction-Related Genes and Pathways from Rohu, Labeo rohita (Hamilton).
- Author
-
Sahu DK, Panda SP, Meher PK, Das P, Routray P, Sundaray JK, Jayasankar P, and Nandi S
- Subjects
- Animals, Female, Male, Cyprinidae physiology, Fish Proteins biosynthesis, Gene Expression Regulation physiology, Reproduction physiology, Transcriptome physiology
- Abstract
Rohu is a leading candidate species for freshwater aquaculture in South-East Asia. Unlike common carp the monsoon breeding habit of rohu restricts its seed production beyond season indicating strong genetic control over spawning. Genetic information is limited in this regard. The problem is exacerbated by the lack of genomic-resources. We identified 182 reproduction-related genes previously by Sanger-sequencing which were less to address the issue of seasonal spawning behaviour of this important carp. Therefore, the present work was taken up to generate transcriptome profile by mRNAseq. 16 GB, 72 bp paired end (PE) data was generated from the pooled-RNA of twelve-tissues from pre-spawning rohu using IlluminaGA-II-platform. There were 64.97 million high-quality reads producing 62,283 contigs and 88,612 numbers of transcripts using velvet and oases programs, respectively. Gene ontology annotation identified 940 reproduction-related genes consisting of 184 mainly associated with reproduction, 223 related to hormone-activity and receptor-binding, 178 receptor-activity and 355 embryonic-development related-proteins. The important reproduction-relevant pathways found in KEGG analysis were GnRH-signaling, oocyte-meiosis, steroid-biosynthesis, steroid-hormone biosynthesis, progesterone-mediated oocyte-maturation, retinol-metabolism, neuroactive-ligand-receptor interaction, neurotrophin-signaling and photo-transduction. Twenty nine simple sequence repeat containing sequences were also found out of which 12 repeat loci were polymorphic with mean expected-&-observed heterozygosity of 0.471 and 0.983 respectively. Quantitative RT-PCR analyses of 13-known and 6-unknown transcripts revealed differences in expression level between preparatory and post-spawning phase. These transcriptomic sequences have significantly increased the genetic-&-genomic resources for reproduction-research in Labeo rohita.
- Published
- 2015
- Full Text
- View/download PDF
78. Genetic variations in NADPH-CYP450 oxidoreductase in a Czech Slavic cohort.
- Author
-
Tomková M, Panda SP, Šeda O, Baxová A, Hůlková M, Siler Masters BS, and Martásek P
- Subjects
- Adult, Amino Acid Substitution, Base Sequence, Cohort Studies, Cytochrome P-450 Enzyme System chemistry, Cytochrome P-450 Enzyme System metabolism, Czech Republic, DNA genetics, Female, Gene Frequency, Genetic Variation, Haplotypes, Humans, Infant, Newborn, Kinetics, Linkage Disequilibrium, Male, Models, Molecular, Mutation, Missense, Protein Conformation, Cytochrome P-450 Enzyme System genetics, Polymorphism, Single Nucleotide
- Abstract
Aim: Estimating polymorphic allele frequencies of the NADPH-CYP450 oxidoreductase (POR) gene in a Czech Slavic population., Methods: The POR gene was analyzed in 322 individuals from a control cohort by sequencing and high resolution melting analysis., Results: We identified seven unreported SNP genetic variations, including two SNPs in the 5' flanking region (g.4965C>T and g.4994G>T), one intronic variant (c.1899-20C>T), one synonymous SNP (p.20Ala=) and three nonsynonymous SNPs (p.Thr29Ser, p.Pro384Leu and p.Thr529Met). The p.Pro384Leu variant exhibited reduced enzymatic activities compared with wild-type., Conclusion: New POR variant identification indicates the number of uncommon variants might be specific for each subpopulation being investigated, particularly germane to the singular role that POR plays in providing reducing equivalents to all CYP450s in the endoplasmic reticulum. Original submitted 15 September 2014; Revision submitted 17 November 2014.
- Published
- 2015
- Full Text
- View/download PDF
79. Differential calmodulin-modulatory and electron transfer properties of neuronal nitric oxide synthase mu compared to the alpha variant.
- Author
-
Panda SP, Li W, Venkatakrishnan P, Chen L, Astashkin AV, Masters BS, Feng C, and Roman LJ
- Subjects
- Amino Acid Sequence physiology, Animals, Calmodulin chemistry, Cytochromes c metabolism, Electron Transport physiology, Flavin Mononucleotide metabolism, Heme chemistry, Heme metabolism, Isoenzymes chemistry, Isoenzymes physiology, Nitric Oxide biosynthesis, Nitric Oxide Synthase Type I chemistry, Protein Binding, Rats, Calmodulin metabolism, Nitric Oxide Synthase Type I physiology
- Abstract
Neuronal nitric oxide synthase μ (nNOSμ) contains 34 additional residues in an autoregulatory element compared to nNOSα. Cytochrome c and flavin reductions in the absence of calmodulin (CaM) were faster in nNOSμ than nNOSα, while rates in the presence of CaM were smaller. The magnitude of stimulation by CaM is thus notably lower in nNOSμ. No difference in NO production was observed, while electron transfer between the FMN and heme moieties and formation of an inhibitory ferrous-nitrosyl complex were slower in nNOSμ. Thus, the insert affects electron transfer rates, modulation of electron flow by CaM, and heme-nitrosyl complex formation., (© 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
80. Conditional deletion of cytochrome p450 reductase in osteoprogenitor cells affects long bone and skull development in mice recapitulating antley-bixler syndrome: role of a redox enzyme in development.
- Author
-
Panda SP, Guntur AR, Polusani SR, Fajardo RJ, Gakunga PT, Roman LJ, and Masters BS
- Subjects
- Abnormalities, Multiple genetics, Abnormalities, Multiple metabolism, Abnormalities, Multiple physiopathology, Animals, Antley-Bixler Syndrome Phenotype genetics, Antley-Bixler Syndrome Phenotype metabolism, Antley-Bixler Syndrome Phenotype physiopathology, Down-Regulation genetics, Female, Fibroblast Growth Factors genetics, Fibroblast Growth Factors metabolism, Male, Mesenchymal Stem Cells metabolism, Mesenchymal Stem Cells physiology, Mice, Mice, Knockout, Mutation genetics, NADPH-Ferrihemoprotein Reductase metabolism, Oxidation-Reduction, Signal Transduction genetics, Signal Transduction physiology, Skull growth & development, Skull metabolism, Stem Cells physiology, Tibia growth & development, Tibia metabolism, Up-Regulation genetics, Bone Development genetics, Bone Development physiology, NADPH-Ferrihemoprotein Reductase genetics, Sequence Deletion genetics, Stem Cells metabolism
- Abstract
NADPH-cytochrome P450 oxidoreductase (POR) is the primary electron donor for cytochromes P450, dehydrocholesterol reductase, heme oxygenase, and squalene monooxygenase. Human patients with specific mutations in POR exhibit severe developmental malformations including disordered steroidogenesis, sexual ambiguities and various bone defects, similar to those seen in patients with Antley-Bixler syndrome (ABS). To probe the role of POR during bone development, we generated a conditional knockout mouse (CKO) by cross breeding Por (lox/lox) and Dermo1 Cre mice. CKO mice were smaller than their littermate controls and exhibited significant craniofacial and long bone abnormalities. Differential staining of the CKO mice skull bases shows premature fusion of the sphenooccipital and basioccipital-exoccipital synchondroses. Class III malocclusion was noted in adult knockout mice with an unusual overgrowth of the lower incisors. Shorter long bones were observed along with a reduction in the bone volume fraction, measured by microCT, in the Por-deleted mice compared to age- and sex-matched littermate controls. Concerted up- or down-regulation of proteins in the FGF signaling pathway observed by immunohistochemistry in the tibia samples of CKO mice compared to wild type controls shows a decrease in the FGF signaling pathway. To our knowledge, this is the first report of a mouse model that recapitulates both skull and long bone defects upon Por deletion, offering an approach to study the sequelae of POR mutations. This unique model demonstrates that P450 metabolism in bone itself is potentially important for proper bone development, and that an apparent link exists between the POR and FGF signaling pathways, begging the question of how an oxidation-reduction flavoprotein affects developmental and cellular signaling processes.
- Published
- 2013
- Full Text
- View/download PDF
81. Identification of reproduction-related genes and SSR-markers through expressed sequence tags analysis of a monsoon breeding carp rohu, Labeo rohita (Hamilton).
- Author
-
Sahu DK, Panda SP, Panda S, Das P, Meher PK, Hazra RK, Peatman E, Liu ZJ, Eknath AE, and Nandi S
- Subjects
- Animals, Brain cytology, Female, Gene Expression Profiling, Gene Expression Regulation, Gene Frequency, Gene Library, Genetic Loci, Heterozygote, Liver cytology, Male, Ovary cytology, Pituitary Gland cytology, Polymorphism, Genetic, Real-Time Polymerase Chain Reaction, Seasons, Carps genetics, Expressed Sequence Tags, Fish Proteins genetics, Microsatellite Repeats, Reproduction genetics, Testis cytology
- Abstract
Labeo rohita (Ham.) also called rohu is the most important freshwater aquaculture species on the Indian sub continent. Monsoon dependent breeding restricts its seed production beyond season indicating a strong genetic control about which very limited information is available. Additionally, few genomic resources are publicly available for this species. Here we sought to identify reproduction-relevant genes from normalized cDNA libraries of the brain-pituitary-gonad-liver (BPGL-axis) tissues of adult L. rohita collected during post preparatory phase. 6161 random clones sequenced (Sanger-based) from these libraries produced 4642 (75.34%) high-quality sequences. They were assembled into 3631 (78.22%) unique sequences composed of 709 contigs and 2922 singletons. A total of 182 unique sequences were found to be associated with reproduction-related genes, mainly under the GO term categories of reproduction, neuro-peptide hormone activity, hormone and receptor binding, receptor activity, signal transduction, embryonic development, cell-cell signaling, cell death and anti-apoptosis process. Several important reproduction-related genes reported here for the first time in L. rohita are zona pellucida sperm-binding protein 3, aquaporin-12, spermine oxidase, sperm associated antigen 7, testis expressed 261, progesterone receptor membrane component, Neuropeptide Y and Pro-opiomelanocortin. Quantitative RT-PCR-based analyses of 8 known and 8 unknown transcripts during preparatory and post-spawning phase showed increased expression level of most of the transcripts during preparatory phase (except Neuropeptide Y) in comparison to post-spawning phase indicating possible roles in initiation of gonad maturation. Expression of unknown transcripts was also found in prolific breeder common carp and tilapia, but levels of expression were much higher in seasonal breeder rohu. 3631 unique sequences contained 236 (6.49%) putative microsatellites with the AG (28.16%) repeat as the most frequent motif. Twenty loci showed polymorphism in 36 unrelated individuals with allele frequency ranging from 2 to 7 per locus. The observed heterozygosity ranged from 0.096 to 0.774 whereas the expected heterozygosity ranged from 0.109 to 0.801. Identification of 182 important reproduction-related genes and expression pattern of 16 transcripts in preparatory and post-spawning phase along with 20 polymorphic EST-SSRs should be highly useful for the future reproductive molecular studies and selection program in Labeo rohita., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
82. Intra- and inter-molecular effects of a conserved arginine residue of neuronal and inducible nitric oxide synthases on FMN and calmodulin binding.
- Author
-
Panda SP, Polusani SR, Kellogg DL 3rd, Venkatakrishnan P, Roman MG, Demeler B, Masters BS, and Roman LJ
- Subjects
- Animals, Cell Line, Conserved Sequence, Electron Transport, Kinetics, Mice, Mutation, Nitric Oxide Synthase Type I genetics, Nitric Oxide Synthase Type I isolation & purification, Nitric Oxide Synthase Type II genetics, Nitric Oxide Synthase Type II isolation & purification, Protein Binding, Rats, Structure-Activity Relationship, Ultracentrifugation, Arginine, Calmodulin metabolism, Flavin Mononucleotide metabolism, Nitric Oxide Synthase Type I chemistry, Nitric Oxide Synthase Type I metabolism, Nitric Oxide Synthase Type II chemistry, Nitric Oxide Synthase Type II metabolism
- Abstract
Nitric oxide synthases (NOSs) synthesize nitric oxide (NO), a signaling molecule, from l-arginine, utilizing electrons from NADPH. NOSs are flavo-hemo proteins, with two flavin molecules (FAD and FMN) and one heme per monomer, which require the binding of calcium/calmodulin (Ca(2+)/CaM) to produce NO. It is therefore important to understand the molecular factors influencing CaM binding from a structure/function perspective. A crystal structure of the CaM-bound iNOS FMN-binding domain predicted a salt bridge between R536 of human iNOS and E47 of CaM. To characterize the interaction between the homologous Arg of rat nNOS (R753) and murine iNOS (R530) with CaM, the Arg was mutated to Ala and, in iNOS, to Glu. The mutation weakens the interaction between nNOS and CaM, decreasing affinity by ~3-fold. The rate of electron transfer from FMN is greatly attenuated; however, little effect on electron transfer from FAD is observed. The mutated proteins showed reduced FMN binding, from 20% to 60%, suggesting an influence of this residue on FMN incorporation. The weakened FMN binding may be due to conformational changes caused by the arginine mutation. Our data show that this Arg residue plays an important role in CaM binding and influences FMN binding., (Published by Elsevier Inc.)
- Published
- 2013
- Full Text
- View/download PDF
83. Altered human CYP3A4 activity caused by Antley-Bixler syndrome-related variants of NADPH-cytochrome P450 oxidoreductase measured in a robust in vitro system.
- Author
-
Moutinho D, Marohnic CC, Panda SP, Rueff J, Masters BS, and Kranendonk M
- Subjects
- Antley-Bixler Syndrome Phenotype genetics, Biotransformation, Catalysis, Cell Membrane enzymology, Escherichia coli genetics, Fluoresceins metabolism, Humans, In Vitro Techniques, Microsomes, Liver enzymology, Mutation, Plasmids, Substrate Specificity, Antley-Bixler Syndrome Phenotype enzymology, Cytochrome P-450 CYP3A metabolism, Genetic Variation, NADPH-Ferrihemoprotein Reductase genetics
- Abstract
NADPH-cytochrome P450 oxidoreductase (CYPOR) variants have been described in patients with perturbed steroidogenesis and sexual differentiation, related to Antley-Bixler syndrome (ABS). It is important to determine the effect of these variants on CYP3A4, the major drug-metabolizing cytochrome P450 (P450) in humans. In this study, 12 CYPOR_ABS variants were separately coexpressed with CYP3A4 in a robust in vitro system to evaluate the effects of these variants on CYP3A4 activity in a milieu that recapitulates the stoichiometry of the mammalian systems. Full-length CYPOR variants were coexpressed with CYP3A4, resulting in relative expression levels comparable to those found in hepatic tissue. Dibenzylfluorescein (DBF), a CYP3A-specific reporter substrate (Biopharm Drug Dispos 24:375-384, 2003), was used to compare the variants and wild-type (WT) CYPOR activities with that of human liver microsomes. CYP3A4, combined with WT CYPOR, demonstrated kinetic parameters (k(cat) and K(m)) equal to those for pooled human liver microsomes. CYPOR variants Y181D, Y459H, V492E, L565P, and R616X all demonstrated maximal loss of CYP3A4 catalytic efficiency, whereas R457H and G539R retained ∼10 and 30% activities, respectively. Conversely, variants P228L, M263V, A287P, and G413S each showed WT-like capacity (k(cat)/K(m)), with the A287P variant being formerly reported to exhibit substantially lower catalytic efficiency. In addition, Q153R exhibited 60% of WT CYPOR capacity to support the DBF O-debenzylation reaction, contradicting increased catalytic efficiency (k(cat)/K(m)) relative to that for the WT, reported previously. Our data indicate the importance of use of simulated, validated in vitro systems, employing full-length proteins with appropriate stoichiometric incorporation of protein partners, when pharmacogenetic predictions are to be made for P450-mediated biotransformation.
- Published
- 2012
- Full Text
- View/download PDF
84. Prevalence of occult hepatitis B amongst Indian human immunodeficiency virus type 1 infected individuals-a pilot study.
- Author
-
Sen S, Panda SP, Shanmuganandan K, Gupta R, and Praharaj A
- Abstract
Background: The diagnosis of hepatitis B is routinely based on the detection of hepatitis B surface antigen (HBsAg) only. However, occult hepatitis B virus (HBV) infection (OBI), which is defined as infection with positive hepatitis B core antibody (anti-HBc) antibodies, positive DNA (deoxyribonucleic acid) PCR (polymerase chain reaction), and undetectable HBsAg, as well as anti-HBs antibodies in serum or plasma of HBV infected individuals, will remain undetected using this screening diagnostic approach of detecting HBsAg. The current study aims in studying the prevalence of the OBI amongst human immunodeficiency virus type 1 (HIV-1) infected individuals who have not been exposed to anti-retroviral therapy., Method: Estimation of HBsAg, anti-HBs, and anti-HBc total antibody status amongst 100 HIV-1 infected study participants was carried out using enzyme-linked immunosorbent assay (ELISA) kits. Detection of HBV-DNA was carried out by in-house qualitative PCR. CD4 + T lymphocyte counts were analysed using Becton Dickinson's (BD) FACSCount™ system., Results: The median age of the HIV-1 infected study population was 35 years (range: 22-67), with the gender distribution being 53 males and 47 females. The mean CD4 T lymphocyte count of the study participants was 210/mm(3). Overall, serological evidence of HBV infection was observed in 28% of the HIV-1 infected study participants. There was 5% seropositivity for HBsAg, of which 2% were additionally positive for HBV-DNA-PCR. "Anti-HBc alone" status was seen in 18% of study participants, this being statistically higher in those with CD4 T lymphocyte counts < 200/mm(3). While there was a single specimen with co-positivity for anti-HBc total antibodies and HBV-DNA, 5% of the in the study population exhibited anti-HBs antibodies positivity, with one sample exhibiting dual positivity for HBsAg and anti-HBs antibodies., Conclusion: Occult HBV infections may contribute to chronic liver damage, and associ-ated reactivation amongst immunocompromised individuals, HIV-1 in-fected being a subset of them. "Anti-HBc" testing followed by HBV-DNA detection by PCR can be utilised for such populations to detect OBIs. Early detection of hepatitis B viraemia will be important for deciding the antiviral therapeutic protocol so as to avoid evolution of antiviral resistance in the circulating HBV strains in HIV-1 infected individuals harbouring OBIs.
- Published
- 2012
- Full Text
- View/download PDF
85. Mutations of human cytochrome P450 reductase differentially modulate heme oxygenase-1 activity and oligomerization.
- Author
-
Marohnic CC, Huber Iii WJ, Patrick Connick J, Reed JR, McCammon K, Panda SP, Martásek P, Backes WL, and Masters BS
- Subjects
- Flavin Mononucleotide chemistry, Flavin Mononucleotide genetics, Flavin Mononucleotide metabolism, Flavin-Adenine Dinucleotide chemistry, Flavin-Adenine Dinucleotide genetics, Flavin-Adenine Dinucleotide metabolism, Heme chemistry, Heme genetics, Heme metabolism, Heme Oxygenase-1 genetics, Heme Oxygenase-1 metabolism, Humans, Multienzyme Complexes genetics, Multienzyme Complexes metabolism, NADPH-Ferrihemoprotein Reductase metabolism, Oxidoreductases Acting on CH-CH Group Donors chemistry, Oxidoreductases Acting on CH-CH Group Donors genetics, Oxidoreductases Acting on CH-CH Group Donors metabolism, Heme Oxygenase-1 chemistry, Multienzyme Complexes chemistry, Mutation, Missense, NADPH-Ferrihemoprotein Reductase chemistry, NADPH-Ferrihemoprotein Reductase genetics, Protein Multimerization
- Abstract
Genetic variations in POR, encoding NADPH-cytochrome P450 oxidoreductase (CYPOR), can diminish the function of numerous cytochromes P450, and also have the potential to block degradation of heme by heme oxygenase-1 (HO-1). Purified full-length human CYPOR, HO-1, and biliverdin reductase were reconstituted in lipid vesicles and assayed for NADPH-dependent conversion of heme to bilirubin. Naturally-occurring human CYPOR variants queried were: WT, A115V, Y181D, P228L, M263V, A287P, R457H, Y459H, and V492E. All CYPOR variants exhibited decreased bilirubin production relative to WT, with a lower apparent affinity of the CYPOR-HO-1 complex than WT. Addition of FMN or FAD partially restored the activities of Y181D, Y459H, and V492E. When mixed with WT CYPOR, only the Y181D CYPOR variant inhibited heme degradation by sequestering HO-1, whereas Y459H and V492E were unable to inhibit HO-1 activity suggesting that CYPOR variants might have differential binding affinities with redox partners. Titrating the CYPOR-HO-1 complex revealed that the optimal CYPOR:HO-1 ratio for activity was 1:2, lending evidence in support of productive HO-1 oligomerization, with higher ratios of CYPOR:HO-1 showing decreased activity. In conclusion, human POR mutations, shown to impact P450 activities, also result in varying degrees of diminished HO-1 activity, which may further complicate CYPOR deficiency., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
86. Structural basis for human NADPH-cytochrome P450 oxidoreductase deficiency.
- Author
-
Xia C, Panda SP, Marohnic CC, Martásek P, Masters BS, and Kim JJ
- Subjects
- Flavin-Adenine Dinucleotide, Humans, Molecular Structure, NADPH-Ferrihemoprotein Reductase deficiency, Polymorphism, Genetic, Trypsin metabolism, Mutation, Missense, NADPH-Ferrihemoprotein Reductase chemistry, Protein Folding
- Abstract
NADPH-cytochrome P450 oxidoreductase (CYPOR) is essential for electron donation to microsomal cytochrome P450-mediated monooxygenation in such diverse physiological processes as drug metabolism (approximately 85-90% of therapeutic drugs), steroid biosynthesis, and bioactive metabolite production (vitamin D and retinoic acid metabolites). Expressed by a single gene, CYPOR's role with these multiple redox partners renders it a model for understanding protein-protein interactions at the structural level. Polymorphisms in human CYPOR have been shown to lead to defects in bone development and steroidogenesis, resulting in sexual dimorphisms, the severity of which differs significantly depending on the degree of CYPOR impairment. The atomic structure of human CYPOR is presented, with structures of two naturally occurring missense mutations, V492E and R457H. The overall structures of these CYPOR variants are similar to wild type. However, in both variants, local disruption of H bonding and salt bridging, involving the FAD pyrophosphate moiety, leads to weaker FAD binding, unstable protein, and loss of catalytic activity, which can be rescued by cofactor addition. The modes of polypeptide unfolding in these two variants differ significantly, as revealed by limited trypsin digestion: V492E is less stable but unfolds locally and gradually, whereas R457H is more stable but unfolds globally. FAD addition to either variant prevents trypsin digestion, supporting the role of the cofactor in conferring stability to CYPOR structure. Thus, CYPOR dysfunction in patients harboring these particular mutations may possibly be prevented by riboflavin therapy in utero, if predicted prenatally, or rescued postnatally in less severe cases.
- Published
- 2011
- Full Text
- View/download PDF
87. Regulation of gap junction function and Connexin 43 expression by cytochrome P450 oxidoreductase (CYPOR).
- Author
-
Polusani SR, Kar R, Riquelme MA, Masters BS, and Panda SP
- Subjects
- Animals, Cell Line, Tumor, Gap Junctions genetics, Gap Junctions metabolism, Gene Knockdown Techniques, Humans, Mice, Mice, Knockout, NADPH-Ferrihemoprotein Reductase genetics, Connexin 43 genetics, Gap Junctions physiology, Gene Expression Regulation, Developmental, NADPH-Ferrihemoprotein Reductase physiology, Osteogenesis genetics
- Abstract
Cytochrome P450 oxidoreductase (CYPOR) is a microsomal electron-transferring enzyme containing both FAD and FMN as co-factors, which provides the reducing equivalents to various redox partners, such as cytochromes P450 (CYPs), heme oxygenase (HO), cytochrome b(5) and squalene monooxygenase. Human patients with severe forms of CYPOR mutation show bone defects such as cranio- and humeroradial synostoses and long bone fractures, known as Antley-Bixler-like Syndrome (ABS). To elucidate the role of CYPOR in bone, we knocked-down CYPOR in multiple osteoblast cell lines using RNAi technology. In this study, knock-down of CYPOR decreased the expression of Connexin 43 (Cx43), known to play a critical role in bone formation, modeling, and remodeling. Knock-down of CYPOR also decreased Gap Junction Intercellular Communication (GJIC) and hemichannel activity. Promoter luciferase assays revealed that the decrease in expression of Cx43 in CYPOR knock-down cells was due to transcriptional repression. Primary osteoblasts isolated from bone specific Por knock-down mice calvariae confirmed the findings in the cell lines. Taken together, our study provides novel insights into the regulation of gap junction function by CYPOR and suggests that Cx43 may play an important role(s) in CYPOR-mediated bone defects seen in patients., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
88. Evaluation of analgesic and anti-inflammatory activity of diospyros cordifolia extract.
- Author
-
Das S, Haldar PK, Pramanik G, Panda SP, and Bera S
- Subjects
- Analgesics isolation & purification, Animals, Anti-Inflammatory Agents isolation & purification, Anti-Inflammatory Agents, Non-Steroidal isolation & purification, Diclofenac, Dose-Response Relationship, Drug, Edema chemically induced, Female, Male, Mice, Pain drug therapy, Pain Measurement, Plant Extracts pharmacology, Plant Stems, Rats, Analgesics therapeutic use, Anti-Inflammatory Agents therapeutic use, Anti-Inflammatory Agents, Non-Steroidal therapeutic use, Diospyros chemistry, Edema drug therapy, Phytotherapy, Plant Extracts therapeutic use
- Abstract
In this study we evaluated the analgesic and anti-inflammatory activities of the methanol extract of stem bark of Diospyros cordifolia (MEDC) Roxb. The analgesic effects of the stem bark of the plant was assessed in mice using the tail-flick method while carrageenan, histamine and dextran induced paw oedema was used to study the antiinflammatory effects in rats. The MEDC exhibited significant (p<0.01) analgesic effects comparable to the reference drug diclofenac sodium. MEDC also was evaluated for its anti-inflammatory potential against carrageenan, histamine and dextran induced rat paw edema. The methanol extract (25 and 50 mg / kg body weight) exhibited significant (p<0.01) activity against all phlogistic agents used in a dose dependent manner. All these effects were compared with reference drug phenylbutazone (100 mg/kg body weight).
- Published
- 2011
89. Hepatoprotective activity of Cyperus tegetum rhizome against paracetamol-induced liver damage in rats.
- Author
-
Haldar PK, Bera S, Panda SP, Bhattacharya S, Chaulya NC, and Mukherjee A
- Subjects
- Acetaminophen toxicity, Analgesics, Non-Narcotic toxicity, Animals, Lipid Peroxidation drug effects, Liver pathology, Liver Function Tests, Male, Methanol, Rats, Rats, Wistar, Rhizome, Thiobarbituric Acid Reactive Substances metabolism, Chemical and Drug Induced Liver Injury prevention & control, Cyperus, Plant Extracts pharmacology, Protective Agents pharmacology
- Abstract
In present study the methanol extract of Cyperus tegetum rhizome (MECT) was evaluated for its effect on paracetamol-induced liver damage in Wistar rats. Serum biochemical parameters viz. serum glutamine oxaloacetate transaminase (SGOT), serum glutamine pyruvate transaminase (SGPT), serum alkaline phosphatase (ALP), total serum protein, total bilirubin content and liver biochemical parameters such as thiobarbituric acid reactive substances (TBARS) and reduced glutathione content were estimated. Biochemical and histopathological observations indicated that MECT had remarkable hepatoprotective effect against paracetamol-induced liver damage in rats.
- Published
- 2011
- Full Text
- View/download PDF
90. Antidiabetic and antioxidant activity of Swietenia mahagoni in streptozotocin-induced diabetic rats.
- Author
-
Panda SP, Haldar PK, Bera S, Adhikary S, and Kandar CC
- Subjects
- Animals, Antioxidants administration & dosage, Antioxidants toxicity, Blood Glucose analysis, Body Weight drug effects, Catalase metabolism, Diabetes Mellitus, Experimental blood, Diabetes Mellitus, Experimental chemically induced, Diabetes Mellitus, Experimental metabolism, Dose-Response Relationship, Drug, Female, Glutathione metabolism, Hypoglycemic Agents administration & dosage, Hypoglycemic Agents toxicity, Kidney drug effects, Kidney enzymology, Kidney metabolism, Lethal Dose 50, Liver drug effects, Liver enzymology, Liver metabolism, Male, Mice, Oxidative Stress drug effects, Plant Extracts administration & dosage, Plant Extracts toxicity, Rats, Rats, Wistar, Thiobarbituric Acid Reactive Substances analysis, Antioxidants therapeutic use, Diabetes Mellitus, Experimental drug therapy, Hypoglycemic Agents therapeutic use, Meliaceae chemistry, Phytotherapy, Plant Bark chemistry, Plant Extracts therapeutic use
- Abstract
Context: Swietenia mahagoni L. Jacq. (Meliaceae) is a medium to large evergreen tree native to Southern Florida, Cuba, The Bahamas, Hispaniola, and Jamaica., Objective: To evaluate the antidiabetic and antioxidant potential of S. mahagoni bark., Materials and Methods: In the present study, the antidiabetic activity of the methanol extract of S. mahagoni (MESM) bark in streptozotocin (STZ; 65 mg/kg body weight)-induced diabetic rats was evaluated. Glibenclamide (0.5 mg/kg; orally) was taken as the reference drug. The blood glucose levels and body weights were measured every 5th day over a period of 15 days. Antioxidant effects were assayed in diabetic rats by estimating thiobarbituric acid reactive substances (TBARS), glutathione (GSH), and catalase (CAT) levels., Results and Discussion: Oral administration of MESM at the doses of 25 and 50 mg/kg b.w. resulted in a significant (p < 0.001) reduction in blood glucose levels in diabetic rats. Body weights were significantly (p < 0.001) reduced in STZ-induced diabetic rats when compared to normal rats, while the extract significantly restored body weight. The present study was further undertaken to evaluate the antioxidant activity of MESM in STZ-induced diabetic rats. Decreased levels of TBARS and increased levels of GSH and CAT activity indicated a reduction in free radical formation in tissues such as the liver and kidney of diabetic rats., Conclusion: These findings showed the significant hypoglycemic and antioxidant activity of the extract (MESM) in diabetic rats.
- Published
- 2010
- Full Text
- View/download PDF
91. Human cytochrome P450 oxidoreductase deficiency caused by the Y181D mutation: molecular consequences and rescue of defect.
- Author
-
Marohnic CC, Panda SP, McCammon K, Rueff J, Masters BS, and Kranendonk M
- Subjects
- Amino Acid Substitution, Carcinogens metabolism, Circular Dichroism, Cytochrome P-450 CYP1A2 chemistry, Cytochrome P-450 CYP1A2 genetics, Cytochrome P-450 CYP1A2 metabolism, Escherichia coli, Flavin Mononucleotide chemistry, Flavin-Adenine Dinucleotide chemistry, Flavin-Adenine Dinucleotide metabolism, Humans, Kinetics, Membranes metabolism, Mutagenesis, Site-Directed, Mutant Proteins chemistry, Mutant Proteins metabolism, Mutation, NADH, NADPH Oxidoreductases metabolism, NADPH-Ferrihemoprotein Reductase chemistry, NADPH-Ferrihemoprotein Reductase genetics, NADPH-Ferrihemoprotein Reductase metabolism, Plasmids, Recombinant Fusion Proteins biosynthesis, Recombinant Fusion Proteins isolation & purification, Spectrometry, Fluorescence, Spectrophotometry, Flavin Mononucleotide metabolism, NADPH-Ferrihemoprotein Reductase deficiency
- Abstract
Patients with congenital adrenal hyperplasia, exhibiting combined CYP17 and CYP21 deficiency, were shown by Arlt et al. (2004) to harbor a 541T-->G mutation in exon 5 of POR (encoding NADPH-cytochrome P450 reductase, CYPOR), which resulted in a Y181D substitution that obliterated electron transfer capacity. Using bacterial expression models, we examined catalytic and physical properties of the human CYPOR Y181D variant. As purified, Y181D lacked flavin mononucleotide (FMN) and NADPH-cytochrome c reductase (NCR) activity but retained normal flavin adenine dinucleotide binding and NADPH utilization. Titration of the purified protein with FMN restored 64 of wild-type (WT) NCR activity in Y181D with an activation constant of approximately 2 microM. As determined by FMN fluorescence quenching, Y181D had K(d)(FMN) = 7.3 microM. Biplasmid coexpression of CYPOR and CYP1A2, at the physiological ratio of approximately 1:10 in the engineered MK_1A2_POR Escherichia coli strain, showed the compromised capacity of Y181D to support CYP1A2-catalyzed metabolism of the procarcinogens 2-aminoanthracene, 2-amino-3-methylimidazo(4,5-f)quinoline, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. Isolated MK1A2_POR membranes confirmed FMN stimulation of Y181D NCR activity with a 1.6 microM activation constant. CYP1A2 ethoxyresorufin-O-dealkylase activity of the MK1A2_POR(Y181D) membranes, undetectable in the absence of added FMN, increased to 37% of MK1A2_POR(WT) membranes with a 1.2 microM FMN activation constant. Therefore, we conclude that compromised FMN binding is the specific molecular defect causing POR deficiency in patients with Y181D mutation and that this defect, in large part, can be overcome in vitro by FMN addition.
- Published
- 2010
- Full Text
- View/download PDF
92. NO formation by neuronal NO-synthase can be controlled by ultrafast electron injection from a nanotrigger.
- Author
-
Beaumont E, Lambry JC, Blanchard-Desce M, Martasek P, Panda SP, van Faassen EE, Brochon JC, Deprez E, and Slama-Schwok A
- Subjects
- Binding Sites, Biocatalysis, Calmodulin pharmacology, Electron Transport drug effects, Flavin-Adenine Dinucleotide metabolism, Hydrogen Bonding, Kinetics, Models, Molecular, NADP metabolism, Nitric Oxide Synthase Type I chemistry, Nitric Oxide Synthase Type I genetics, Photochemical Processes, Point Mutation, Protein Structure, Tertiary, Spectrometry, Fluorescence, Nitric Oxide biosynthesis, Nitric Oxide Synthase Type I metabolism
- Abstract
Nitric oxide synthases (NOSs) are unique flavohemoproteins with various roles in mammalian physiology. Constitutive NOS catalysis is initiated by fast hydride transfer from NADPH, followed by slower structural rearrangements. We used a photoactive nanotrigger (NT) to study the initial electron transfer to FAD in native neuronal NOS (nNOS) catalysis. Molecular modeling and fluorescence spectroscopy showed that selective NT binding to NADPH sites close to FAD is able to override Phe1395 regulation. Ultrafast injection of electrons into the protein electron pathway by NT photoactivation through the use of a femtosecond laser pulse is thus possible. We show that calmodulin, required for NO synthesis by constitutive NOS, strongly promotes intramolecular electron flow (6.2-fold stimulation) by a mechanism involving proton transfer to the reduced FAD(-) site. Site-directed mutagenesis using the S1176A and S1176T mutants of nNOS supports this hypothesis. The NT synchronized the initiation of flavoenzyme catalysis, leading to the formation of NO, as detected by EPR. This NT is thus promising for time-resolved X-ray and other cellular applications.
- Published
- 2009
- Full Text
- View/download PDF
93. Impairment of human CYP1A2-mediated xenobiotic metabolism by Antley-Bixler syndrome variants of cytochrome P450 oxidoreductase.
- Author
-
Kranendonk M, Marohnic CC, Panda SP, Duarte MP, Oliveira JS, Masters BS, and Rueff J
- Subjects
- Catalysis, Formazans metabolism, Humans, NADPH-Ferrihemoprotein Reductase physiology, Oxidation-Reduction, Syndrome, Tetrazolium Salts metabolism, Xenobiotics metabolism, Craniosynostoses genetics, Cytochrome P-450 CYP1A2 genetics, Flavin-Adenine Dinucleotide chemistry, Mutation, NADPH-Ferrihemoprotein Reductase genetics
- Abstract
Y459H and V492E mutations of cytochrome P450 reductase (CYPOR) cause Antley-Bixler syndrome due to diminished binding of the FAD cofactor. To address whether these mutations impaired the interaction with drug-metabolizing CYPs, a bacterial model of human liver expression of CYP1A2 and CYPOR was implemented. Four models were generated: POR(null), POR(wt), POR(YH), and POR(VE), for which equivalent CYP1A2 and CYPOR levels were confirmed, except for POR(null), not containing any CYPOR. The mutant CYPORs were unable to catalyze cytochrome c and MTT reduction, and were unable to support EROD and MROD activities. Activity was restored by the addition of FAD, with V492E having a higher apparent FAD affinity than Y459H. The CYP1A2-activated procarcinogens, 2-aminoanthracene, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, and 2-amino-3-methylimidazo(4,5-f)quinoline, were significantly less mutagenic in POR(YH) and POR(VE) models than in POR(wt), indicating that CYP1A2, and likely other drug-metabolizing CYPs, are impaired by ABS-related POR mutations as observed in the steroidogenic CYPs.
- Published
- 2008
- Full Text
- View/download PDF
94. Oxygen metabolism by endothelial nitric-oxide synthase.
- Author
-
Gao YT, Roman LJ, Martásek P, Panda SP, Ishimura Y, and Masters BSS
- Subjects
- Animals, Arginine metabolism, Biopterins chemistry, Biopterins metabolism, Catalysis, Humans, Nitric Oxide chemistry, Nitric Oxide Synthase Type I chemistry, Nitric Oxide Synthase Type I metabolism, Nitric Oxide Synthase Type III metabolism, Nitrosamines chemistry, Nitrosamines metabolism, Oxygen metabolism, Reactive Oxygen Species metabolism, Recombinant Proteins chemistry, Recombinant Proteins metabolism, Arginine chemistry, Biopterins analogs & derivatives, Nitric Oxide metabolism, Nitric Oxide Synthase Type III chemistry, Oxygen chemistry, Reactive Oxygen Species chemistry
- Abstract
Nitric-oxide synthase (NOS) catalyzes both coupled and uncoupled reactions that generate nitric oxide and reactive oxygen species. Oxygen is often the overlooked substrate, and the oxygen metabolism catalyzed by NOS has been poorly defined. In this paper we focus on the oxygen stoichiometry and effects of substrate/cofactor binding on the endothelial NOS isoform (eNOS). In the presence of both L-arginine and tetrahydrobiopterin, eNOS is highly coupled (>90%), and the measured stoichiometry of O(2)/NADPH is very close to the theoretical value. We report for the first time that the presence of L-arginine stimulates oxygen uptake by eNOS. The fact that nonhydrolyzable L-arginine analogs are not stimulatory indicates that the occurrence of the coupled reaction, rather than the accelerated uncoupled reaction, is responsible for the L-arginine-dependent stimulation. The presence of 5,6,7,8-tetrahydrobiopterin quenched the uncoupled reactions and resulted in much less reactive oxygen species formation, whereas the presence of redox-incompetent 7,8-dihydrobiopterin demonstrates little quenching effect. These results reveal different mechanisms for oxygen metabolism for eNOS as opposed to nNOS and, perhaps, partially explain their functional differences.
- Published
- 2007
- Full Text
- View/download PDF
95. Oxygen metabolism by neuronal nitric-oxide synthase.
- Author
-
Gao YT, Panda SP, Roman LJ, Martásek P, Ishimura Y, and Masters BS
- Subjects
- Animals, Anions, Arginine chemistry, Calmodulin metabolism, Catalysis, Escherichia coli metabolism, Hydrogen Peroxide pharmacology, Kinetics, Models, Chemical, Oxygen Consumption, Reactive Oxygen Species, Substrate Specificity, Superoxides chemistry, Time Factors, Nitric Oxide Synthase Type I metabolism, Oxygen metabolism
- Abstract
Nitric-oxide synthases (NOS) catalyze nitric oxide (NO) formation from the amino acid L-arginine. NOS is known to catalyze more than one reaction: the NO-producing reaction is considered to be the coupled reaction, and the uncoupled reactions are those that produce reactive (reduced) oxygen species (ROS), such as superoxide anion (O-2.) and/or hydrogen peroxide (H2O2). As an oxygenase, NOS has been known for more than two decades, yet there is no complete description of oxygen stoichiometry. The present paper is focused on oxygen stoichiometry and the effects of cofactor binding on the neuronal isoform (nNOS) on oxygen uptake and product formation. Products of the uncoupled reactions are analyzed using diacetyldeuteroheme-substituted horseradish peroxidase as a trapping agent for both O-2. and H2O2. The addition of calmodulin not only stimulated the oxygen uptake rate but also changed the product of the uncoupled reaction, supporting the possibility of two different sites for electron leakage to molecular oxygen. Quantitative analysis of the uncoupled (substrate-free) reaction revealed a stoichiometry close to the theoretical value, and adding L-arginine not only initiates the coupled reaction, but also inhibits oxygen uptake. The presence of tetrahydrobiopterin affects oxygen metabolism by lowering the apparent Km value of nNOS for oxygen in the uncoupled reaction.
- Published
- 2007
- Full Text
- View/download PDF
96. Diminished FAD binding in the Y459H and V492E Antley-Bixler syndrome mutants of human cytochrome P450 reductase.
- Author
-
Marohnic CC, Panda SP, Martásek P, and Masters BS
- Subjects
- Catalysis, Circular Dichroism, Cloning, Molecular, Flavins chemistry, Humans, Kinetics, Models, Molecular, Mutagenesis, NADPH-Ferrihemoprotein Reductase physiology, Oxidation-Reduction, Protein Binding, Syndrome, Craniosynostoses genetics, Flavin-Adenine Dinucleotide chemistry, Mutation, NADPH-Ferrihemoprotein Reductase genetics
- Abstract
Numerous mutations/polymorphisms of the POR gene, encoding NADPH:cytochrome P450 oxidoreductase (CYPOR), have been described in patients with Antley-Bixler syndrome (ABS), presenting with craniofacial dysmorphogenesis, and/or disordered steroidogenesis, exhibiting ambiguous genitalia. CYPOR is the obligate electron donor to 51 microsomal cytochromes P450 that catalyze critical steroidogenic and xenobiotic reactions, and to two heme oxygenase isoforms, among other redox partners. To address the molecular basis of CYPOR dysfunction in ABS patients, the soluble catalytic domain of human CYPOR was bacterially expressed. WT enzyme was green, due to air-stable FMN semiquinone (blue) and oxidized FAD (yellow). The ABS mutant V492E was blue-gray. Flavin analysis indicated that WT had a protein:FAD:FMN ratio of approximately 1:1:1, whereas approximately 1:0.1:0.9 was observed for V492E, which retained 9% of the WT k(cat)/K(m) in NADPH:cytochrome c reductase assays. V492E was reconstituted upon addition of FAD, post-purification, as shown by flavin analysis, activity assay, and near UV-visible CD. Both Y459H and V492E were expressed as membrane anchor-containing proteins, which also exhibited FAD deficiency. CYP4A4-catalyzed omega-hydroxylation of prostaglandin E1 was supported by WT CYPOR but not by either of the ABS mutants. Hydroxylation activity was rescued for both Y459H and V492E upon addition of FAD to the reaction. Based on these findings, decreased FAD-binding affinity is proposed as the basis of the observed loss of CYPOR function in the Y459H and V492E POR mutations in ABS.
- Published
- 2006
- Full Text
- View/download PDF
97. The role of a conserved serine residue within hydrogen bonding distance of FAD in redox properties and the modulation of catalysis by Ca2+/calmodulin of constitutive nitric-oxide synthases.
- Author
-
Panda SP, Gao YT, Roman LJ, Martásek P, Salerno JC, and Masters BS
- Subjects
- Alanine chemistry, Alanine genetics, Amino Acid Sequence, Amino Acid Substitution, Calmodulin genetics, Catalysis, Electron Transport, Flavin-Adenine Dinucleotide metabolism, Humans, Hydrogen Bonding, Molecular Sequence Data, Mutagenesis, Site-Directed, Mutation genetics, NADP metabolism, Nitric Oxide Synthase Type I genetics, Nitric Oxide Synthase Type III genetics, Oxidation-Reduction, Polymerase Chain Reaction, Sequence Homology, Amino Acid, Serine genetics, Threonine chemistry, Threonine genetics, Calcium metabolism, Calmodulin metabolism, Nitric Oxide Synthase Type I metabolism, Nitric Oxide Synthase Type III metabolism, Serine chemistry
- Abstract
The crystal structure of the neuronal nitric-oxide synthase (nNOS) NADPH/FAD binding domain indicated that Ser-1176 is within hydrogen bonding distance of Asp-1393 and the O4 atom of FAD and is also near the N5 atom of FAD (3.7 A). This serine residue is conserved in most of the ferredoxin-NADP+ reductase family of proteins and is important in electron transfer. In the present study, the homologous serines of both nNOS (Ser-1176) and endothelial nitric-oxide synthase (eNOS) (Ser-942) were mutated to threonine and alanine. Both substitutions yielded proteins that exhibited decreased rates of electron transfer through the flavin domains, in the presence and absence of Ca2+/CaM, as measured by reduction of potassium ferricyanide and cytochrome c. Rapid kinetics measurements of flavin reduction of all the mutants also showed a decrease in the rate of flavin reduction, in the absence and presence of Ca2+/CaM, as compared with the wild type proteins. The serine to alanine substitution caused both nNOS and eNOS to synthesize NO more slowly; however, the threonine mutants gave equal or slightly higher rates of NO production compared with the wild type enzymes. The midpoint redox potential measurements of all the redox centers revealed that wild type and threonine mutants of both nNOS and eNOS are very similar. However, the redox potentials of the FMN/FMNH* couple for alanine substitutions of both nNOS and eNOS are >100 mV higher than those of wild type proteins and are positive. These data presented here suggest that hydrogen bonding of the hydroxyl group of serine or threonine with the isoalloxazine ring of FAD and with the amino acids in its immediate milieu, particularly nNOS Asp-1393, affects the redox potentials of various flavin states, influencing the rate of electron transfer.
- Published
- 2006
- Full Text
- View/download PDF
98. Detection of nitrous oxide in the neuronal nitric oxide synthase reaction by gas chromatography-mass spectrometry.
- Author
-
Ishimura Y, Gao YT, Panda SP, Roman LJ, Masters BS, and Weintraub ST
- Subjects
- Animals, Escherichia coli, Gas Chromatography-Mass Spectrometry methods, Nitric Oxide Synthase Type I metabolism, Nitrous Oxide chemistry, Nitrous Oxide metabolism
- Abstract
Using headspace gas chromatography-mass spectrometry, we detected significant amounts of nitrous oxide in the reaction products of the monooxygenase reaction catalyzed by neuronal nitric oxide synthase. Nitrous oxide is a dimerization product of nitroxyl anion; its presence in the reaction products indicates that the nitroxyl anion is a product of the neuronal nitric oxide synthase-catalyzed reaction.
- Published
- 2005
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.