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Downstream processing in the manufacturing biopharmaceutical industry is a multistep process separating the desired product from process- and product-related impurities. However, removing product-related impurities, such as product variants, without compromising the product yield or prolonging the process time due to extensive quality control analytics, remains a major challenge. Here, we show how mechanistic model-based monitoring, based on analytical quality control data, can predict product variants by modeling their chromatographic separation during product polishing with reversed phase chromatography. The system was described by a kinetic dispersive model with a modified Langmuir isotherm. Solely quality control analytical data on product and product variant concentrations were used to calibrate the model. This model-based monitoring approach was developed for an insulin purification process. Industrial materials were used in the separation of insulin and two insulin variants, one eluting at the product peak front and one eluting at the product peak tail. The model, fitted to analytical data, used one component to simulate each protein, or two components when a peak displayed a shoulder. This monitoring approach allowed the prediction of the elution patterns of insulin and both insulin variants. The results indicate the potential of using model-based monitoring in downstream polishing at industrial scale to take pooling decisions., (© 2019 American Institute of Chemical Engineers.)

Undesirable effects of the pathogen Botrytis cinerea include reduced quality and quantity of wine grapes. Winemaking is also complicated by the formation of a protein haze in white wines and oxidative browning of red wines. We analyzed proteins in experimental Moravian white wines characterized by their instability and haze formation in bottles during storage despite prior bentonite treatment. To study the relationship of wine proteins and haze, we carried out proteomics on hazy and clear white wines produced with partly or largely botrytized grapes and standard reference wines. Wine proteins were identified after their extraction, electrophoresis, and tryptic digestion by reversed-phase liquid chromatography of peptides, coupled with tandem mass spectrometry. Plant defense proteins, yeast glycoproteins, and various enzymes from Botrytis, particularly hydrolases, were found. As the content of the known haze-active thaumatin-like proteins and chitinases was visually low on stained gels (missing bands) compared to previous studies with unfined wines, other proteins are discussed in terms of the haze formation. As the main novelty, this work reveals the role of high proline-containing proteins in the propensity of white wines to turbidity following prior Botrytis damage of grapes., (© 2019 International Union of Biochemistry and Molecular Biology, Inc.)

Poloxamer P188 is a common nonionic surfactant additive used in cell culture media as a cellular protectant from the hydrodynamic forces and shear stress during bioprocessing. Presence of a hydrophobic high molecular weight impurity contaminant has been shown to compromise its protective properties and lead to batch failure. In this work we present, a reliable, sensitive, and rapid analytical method to detect and quantify the contaminant impurity in poloxamer 188. This method replaces a laborious and time-consuming functional test in the form of a shake flask assay. The method is based upon reversed-phase liquid chromatography with charged aerosol detection, simple mobile phase compositions, and a three-step gradient. The method was optimized to resolve the impurity from the main P188 fraction in less than 10 min. Analytical method qualification and functional test comparison demonstrate equivalent or better high throughput impurity screening performance. Attempts to identify the impurity and establish suitable method positive control standards are also discussed., (© 2019 American Institute of Chemical Engineers.)

Production of knob and hole dual light chain bispecific antibodies poses several unique challenges for development of a feasible industrial scale manufacturing process. We developed an efficient process for the assembly and purification of knob and hole dual light chain bispecific antibodies. Two distinct half-antibodies targeting two different antigens were expressed separately in Escherichia coli cells and captured independently using Protein A chromatography. When combined, the knob and hole mutations in the CH3 domains promoted heterodimer formation. The hinge region disulfides were reduced and reoxidized to form the disulfide bridge between the two complementary half antibodies. Unreacted half antibodies, noncovalently linked homodimers, covalently linked homodimers, and noncovalently linked heterodimers are impurities closely related to the product of interest and are challenging to remove by standard processes. Characterization of the molecular properties of the half antibodies and high-throughput screening predicted column chromatography performance and allowed for rapid development of downstream purification steps for removal of unique product-related and process-related impurities. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:397-404, 2018., (© 2018 American Institute of Chemical Engineers.)

Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels, which are widely distributed in the central and peripheral nervous system. The α6β2* nAChR is an important subtype, which is closely associated with nicotine addiction and movement disorders etc. α-conotoxin TxIB with 16-amino acid residues specifically targets α6β2* nAChR with no obvious effect on other nAChR subtypes. However, chemical synthesis of TxIB is expensive, and the quantity of native TxIB extracted from cone snail is limited. In the present study, we attempted to obtain TxIB using biological method based on the recombinant expression in Escherichia coli (E. coli). The synthetic gene encoding mature peptide of TxIB was inserted in pET-31b(+) vector and transformed into E. coli strain BLR(DE3)pLysS for expression. The recombinant fusion protein KSI-TxIB-His 6 (KSI, ketosteroid isomerase) was expressed successfully as inclusion body in E. coli, which was purified by Ni-NTA affinity chromatography column and cleaved by cyanogen bromide (CNBr) to release recombinant α-conotoxin TxIB (rTxIB). Then, rTxIB was purified by reverse-phase high-performance liquid chromatography (RP-HPLC) and was identified by electrospray ionization mass spectrometry (ESI-MS). Pharmacological activity of rTxIB was assessed by electrophysiological approaches. The results indicated that it preserved about 50% of potency, but, was even more important, had the same selectivity as the natural conotoxin which may provide an alternative method for quantity production of small peptides with low cost on the premise of not changing their potency., (© 2017 John Wiley & Sons Ltd.)

The salivary agglutinin glycoprotein (SAG) is present in saliva but is also part of the salivary pellicle, playing a seemingly paradoxical role with regard to bacterial homeostasis. On the one hand, SAG aggregates bacteria in solution, thereby preventing bacterial colonization. On the other hand, when bound to the tooth surface, SAG facilitates bacterial colonization and microbial growth. The protein part of SAG is predominantly composed of conserved scavenger receptor cysteine-rich (SRCR) domains. Previously it was found that bacterial binding and aggregation is mediated via a single peptide loop, designated SRCRP2 (P2), within the SRCR domains of SAG. The current data suggest that the SRCR domains also harbour a hydroxyapatite (HA)-binding moiety, SRCRP3 (P3). The observation that P2 and P3 individually play unique roles in the function of SAGs contributes to our understanding of the dual role of SAGs in bacterial binding. Inspired by the bacterial-modulating capacity of SAGs, we created a P3-polyethylene glycol (PEG) conjugate. It was found that a P3 coating resulted in an increased antifouling activity of 20% compared with the uncoated surface in vitro. An additional PEG moiety resulted in an antifouling activity of up to 40% and 30% for Streptococcus mutans and Staphylococcus epidermidis, respectively., (© 2013 Academic Centre for Dentistry Amsterdam, University of Amsterdam and VU University Amsterdam.)

Objectives: Diets consisting of diverse food items provide a wide range of nutrients that can enhance nutritional quality of the diet. Few studies have, however, assessed dietary diversity and its effects on micronutrient health in rural populations in field settings. This study assesses how well Dietary Diversity Score (DDS), an indicator of dietary diversity based on a simple count of food groups consumed, predicts the micronutrient status, focusing on serum vitamin A concentration., Methods: We used cross-sectional data from women in food-insecure northern Kenya where dietary diversity is likely critical for micronutrient health yet under-studied. A linear regression model was applied to examine the relationships between DDS and serum retinol concentration. A logistic regression model was used to test DDS as a predictor of vitamin A insufficiency (serum retinol < 1.05 μmol/l)., Results: DDS had a significant positive effect on serum retinol concentration (t = 2.01, P = 0.045) after adjusting for age, wealth, acute phase reaction, hemoglobin, vitamin A intake and vitamin A supplementation. A one unit increase in DDS by adding an extra food group in one's diet was significantly less likely to have vitamin A insufficiency (OR = 0.64, P = 0.026) after adjusting for the covariates., Conclusions: Our results indicate that diversified diets enhance vitamin A status relative to narrower diets with equivalent vitamin A content. DDS shows a potential as a low-cost, field-friendly method for exploratory assessments of vitamin A status, and a potential as a research tool for human biologists and anthropologists interested in dietary quality and micronutrient health., (Copyright © 2012 Wiley Periodicals, Inc.)

Background: Acetaldehyde is produced during ethanol metabolism predominantly in the liver by alcohol dehydrogenase and rapidly eliminated by oxidation to acetate via aldehyde dehydrogenase. Assessment of circulating acetaldehyde levels in biological matrices is performed by headspace gas chromatography and reverse phase high-performance liquid chromatography (RP-HPLC)., Methods: We have developed an optimized method for the measurement of acetaldehyde by RP-HPLC in hepatoma cell culture medium, blood, and plasma. After sample deproteinization, acetaldehyde was derivatized with 2,4-dinitrophenylhydrazine (DNPH). The reaction was optimized for pH, amount of derivatization reagent, time, and temperature. Extraction methods of the acetaldehyde-hydrazone (AcH-DNP) stable derivative and product stability studies were carried out. Acetaldehyde was identified by its retention time in comparison with AcH-DNP standard, using a new chromatography gradient program, and quantitated based on external reference standards and standard addition calibration curves in the presence and absence of ethanol., Results: Derivatization of acetaldehyde was performed at pH 4.0 with an 80-fold molar excess of DNPH. The reaction was completed in 40 minutes at ambient temperature, and the product was stable for 2 days. A clear separation of AcH-DNP from DNPH was obtained with a new 11-minute chromatography program. Acetaldehyde detection was linear up to 80 μM. The recovery of acetaldehyde was >88% in culture media and >78% in plasma. We quantitatively determined the ethanol-derived acetaldehyde in hepatoma cells, rat blood and plasma with a detection limit around 3 μM. The accuracy of the method was <9% for intraday and <15% for interday measurements, in small volume (70 μl) plasma sampling., Conclusions: An optimized method for the quantitative determination of acetaldehyde in biological systems was developed using derivatization with DNPH, followed by a short RP-HPLC separation of AcH-DNP. The method has an extended linear range, is reproducible and applicable to small-volume sampling of culture media and biological fluids., (Copyright © 2011 by the Research Society on Alcoholism.)

Hemophilia B is a genetic disease of the coagulation system that affects one in 30,000 males worldwide. Recombinant human Factor IX (rhFIX) has been used for hemophilia B treatment, but the amount of active protein generated by these systems is inefficient, resulting in a high-cost production of rhFIX. In this study, we developed an alternative for rhFIX production. We used a retrovirus system to obtain two recombinant cell lines. We first tested rhFIX production in the human embryonic kidney 293 cells (293). Next, we tested a hepatic cell line (HepG2) because FIX is primarily expressed in the liver. Our results reveal that intracellular rhFIX expression was more efficient in HepG2/rhFIX (46%) than in 293/rhFIX (21%). The activated partial thromboplastin time test showed that HepG2/rhFIX expressed biologically active rhFIX 1.5 times higher than 293/rhFIX (P = 0.016). Recovery of rhFIX from the HepG2 by reversed-phase chromatography was straightforward. We found that rhFIX has a pharmacokinetic profile similar to that of FIX purified from human plasma when tested in hemophilic B model. HepG2/rhFIX cell line produced the highest levels of rhFIX, representing an efficient in vitro expression system. This work opens up the possibility of significantly reducing the costs of rhFIX production, with implications for expanding hemophilia B treatment in developing countries., (Copyright © 2011 International Union of Biochemistry and Molecular Biology, Inc.)

Mutation in fibrinogen genes may lead to quantitative or qualitative disorders that result in bleeding, thrombosis or hepatic fibrinogen storage disease. Only three mutations in the fibrinogen γ gene have been identified that cause hepatic endoplasmic reticulum storage of mutant fibrinogen. To investigate the possibility of hepatic fibrinogen storage disease in a 4-year-old male with persistently elevated serum aminotransferases and preserved synthetic function except for a prolonged INR. After informed consent, liver and blood samples were obtained. Liver sections were examined by light microscopy, anti-fibrinogen immunolabelling and electron microscopy. Purified fibrinogen was analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and reverse phase high performance liquid chromatography; DNA sequencing was performed using a BigDye Terminator (v. 3.1) cycle sequencing kit. Four-year-old male with persistently elevated transaminases with an INR 1.5 but otherwise normal synthetic function. Fibrinogen activity and thrombin clotting time were abnormal at 0.47 g/L and 46 s respectively. Hepatic histological examination revealed portal inflammatory infiltrates with bridging fibrosis. Clumped eosinophilic material was observed in hepatocytes that was immunoreactive to fibrinogen antisera. Ultrastructural examination showed cytoplasmic inclusions arrayed in fingerprint-like patterns. DNA sequence analysis revealed heterozygosity for a novel γ314Thr →Pro mutation (fibrinogen AI duPont) in the fibrinogen γ gene. Protein analyses showed normal patterns of Aα, Bβ and γ chains suggesting that the variant γ allele was not expressed in plasma fibrinogen. We describe only the fourth mutation to be identified, γ314Thr→Pro (fibrinogen AI duPont), giving rise to hypofibrinogenaemia and hepatic fibrinogen storage disease., (© 2010 John Wiley & Sons A/S.)

Objective: Intracellular methotrexate (MTX) polyglutamates (MTXGlu) have been shown to be potentially useful biomarkers of clinical response in adult patients with rheumatoid arthritis. The present study was undertaken to measure intracellular MTXGlu concentrations in a cohort of patients with juvenile idiopathic arthritis (JIA) to determine the predictors of MTXGlu variability in these patients., Methods: Blood samples were obtained from patients with JIA who were being treated with a stable dose of MTX for >or=3 months. Clinical data were collected by chart review. Concentrations of MTXGlu(1-7) in red blood cell lysates were quantitated using an innovative ion-pairing chromatography procedure, with detection by mass spectrometry., Results: Patients with JIA from a single center (n = 99; mean +/- SD age 117.8 +/- 56.5 months, 69 female) were included in the analysis. The mean +/- SD dose of MTX was 0.51 +/- 0.25 mg/kg per week, with a median treatment duration of 18 months (interquartile range 3-156 months). MTX was administered subcutaneously in 66 patients (67%). Fifty-six patients (57%) had active arthritis at the time of the clinic visit. Total intracellular MTXGlu (MTXGlu(TOT)) concentrations varied 40-fold, with a mean +/- SD total concentration of 85.8 +/- 48.4 nmoles/liter. Concentrations of each MTXGlu subtype (MTXGlu(1-7)) were measured individually and as a percentage of MTXGlu(TOT) in each patient. MTXGlu(3) was the most prominent subtype identified, comprising 42% of MTXGlu(TOT), and the interindividual variability in the concentration of MTXGlu(3) was the most highly correlated with that of MTXGlu(TOT) (r = 0.96). The route of MTX administration was significantly associated with MTXGlu(1-5) subtypes; higher concentrations of MTXGlu(1 + 2) were observed in patients receiving oral doses of MTX, whereas higher concentrations of MTXGlu(3-5) were observed in patients receiving subcutaneous doses of MTX (P < 0.0001)., Conclusion: In this cohort of patients with JIA, the MTXGlu(TOT) concentration varied 40-fold. Individual MTXGlu metabolites (MTXGlu(1-7)), which have, until now, not been previously reported in patients with JIA, were detected. The route of MTX administration contributed to the variability in concentrations of MTXGlu(1-5).

Umami‐ and kokumi‐taste‐active peptides in Maillard reaction products of enzymatic hydrolysate of bovine bone marrow extract (BBME) were purified and identified by ultrafiltration, gel filtration chromatography, reverse‐phase high‐performance liquid chromatography, liquid chromatography/quadrupole‐time of flight mass spectrometry (LC‐Q‐TOF‐MS/MS) and sensory evaluation. Eight umami and kokumi taste oligopeptides were found in the enzymatic hydrolysate of BBME. After Maillard reaction, the numbers of oligopeptides increased to twelve, such as Ala‐His, Ala‐Val‐His, Gly‐Pro, His‐Gly, Pro‐Ala‐His, Pro‐Val‐Asn‐His, Phe‐Glu‐Ala, Ala‐Ala‐Cys‐Arg, Leu‐Met, Leu‐Thr‐His, Pro‐Gly‐His, Ser‐Thr‐Gly‐Arg, which are linked to a variety of functional properties, such as ACE inhibitor, prolyl endopeptidase inhibitor and dipeptidyl peptidase IV inhibitor, etc. Eight peptides, including Cys‐Pro‐Arg, Ser‐Gly‐Val‐Glu, Pro‐Cys, Cys‐Glu, Cys‐Met‐Thr, Phe‐Glu‐Ala, Ala‐Gln and Leu‐Met, were synthesised and then subjected to sensory evaluation. The evaluation showed that among the eight peptides, Cys‐Pro‐Arg, Pro‐Cys and Leu‐Met led to the distinctly enhanced kokumi taste in blank beef soup. The influence of enzymatic hydrolysis and Maillard reaction to taste‐active components in bovine bone extract including amino acids, nucleotide and peptides. [ABSTRACT FROM AUTHOR]

Biophysical studies on amyloidogenic and aggregation-prone peptides often require large quantities of material. However, solid-phase synthesis, handling, and purification of peptides often present challenges on these scales. Recombinant expression is an attractive alternative because of its low cost, the ability to isotopically label the peptides, and access to sequences exceeding ∼50 residues. However, expression systems that seek to solubilize amyloidogenic peptides suffer from low yields, difficult optimizations, and isolation challenges. We present a general strategy for expressing and isolating amyloidogenic peptides in Escherichia coli by fusion to a polypeptide that drives the expression of attached peptides into bacterial inclusion bodies. This scheme minimizes toxicity during bacterial growth and enables the processing and handling of the peptides in denaturing solutions. Immobilized metal affinity chromatography, reverse phase HPLC, and cyanogen bromide cleavage are used to isolate the peptide, followed by further reverse phase HPLC, which yields milligram quantities of the purified peptide. We demonstrate that driving the peptides into inclusion bodies using fusion to BCL-XL-1/2 is a general strategy for their expression and isolation, as exemplified by the production of 11 peptides species. [ABSTRACT FROM AUTHOR]

A simple method is presented to esterify 1- O-hexadecyl- rac-glycerol using lipases in different organic solvents. The following fatty acids were used: C14∶0, C16∶0, C18∶0, C18∶1, and C18∶2. Monoesterification was achieved by using a limiting amount of the fatty acid. Both the 1- O-hexadecyl-3- O-acylglycerol and the 2- O-acylglycerol were obtained in a total yield of 75% and a ratio of 7∶1 in dichloromethane after 3 d. Chromatographic data for the monoesters, useful for the identification of the natural products, are given (gas-liquid chromatography, thin-layer chromatography, reverse-phase thin-layer chromatography). The structure was confirmed by a chemical synthesis of 1- O-hexadecyl-2- O-hexadecanoylglycerol. The 3- O-glyceride was also formed by acyl migration, as the minor component. The monoesters were separated by column chromatography and characterized by 1H and 13C nuclear magnetic resonance spectra. [ABSTRACT FROM AUTHOR]

Top–down proteomics (TDP) identifies, quantifies, and characterises proteins at the intact proteoform level in complex biological samples to understand proteoform function and cellular mechanisms. However, analysing complex biological samples using TDP is still challenging due to high sample complexity and wide dynamic range. High‐resolution separation methods are often applied prior to mass spectrometry (MS) analysis to decrease sample complexity and increase proteomics throughput. These separation methods, however, may not be efficient enough to characterise low abundance intact proteoforms in complex samples. As such, multidimensional separation techniques (combination of two or more separation methods with high orthogonality) have been developed and applied that demonstrate improved separation resolution and more comprehensive identification in TDP. A suite of multidimensional separation methods that couple various types of liquid chromatography (LC), capillary electrophoresis (CE), and/or gel electrophoresis‐based separation approaches have been developed and applied in TDP to analyse complex biological samples. Here, we reviewed multidimensional separation strategies employed for TDP, summarised current applications, and discussed the gaps that may be addressed in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: The traditional screening method for umami peptide, extracted from porcine bone, was labor‐intensive and time‐consuming. In this study, the rapid screening method and molecular mechanism of umami peptide was investigated. RESULTS: This article showed that a more precisely rapid screening method with composite machine learning and molecular docking was used to screen the potential umami peptide from porcine bone. As reference, 24 reported umami peptides were predicated by composite machine learning, with the accuracy of 86.7%. In this study, potential umami peptide sequences from porcine bone were screened by UMPred‐FRL, Umami‐MRNN Demo, and molecular docking was used to provide further screening. Finally, nine peptides were screened and verified as umami peptides by this method: LREY, HEAL, LAKVH, FQKVVA, HVKELE, AEVKKAP, EAVEKPQS, KALSEEL and KKMFETES. The hydrogen bonding was deemed to be the main interaction force with receptor T1R3, and domain binding sites were Ser146, His121 and Glu277. The result demonstrated the feasibility of machine learning assisted T1R1/T1R3 receptor for rapid screening umami peptides. The screening method would not only adapt to screen umami peptides from porcine bone but possibly applied for other sources. It also provided a reference for rapid screening of umami peptides. CONCLUSION: The manuscript lays a rapid screening method in screening umami peptide, and nine umami peptides from porcine bone were screened and identified. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Top‐down proteomics is emerging as a preferred approach to investigate biological systems, with objectives ranging from the detailed assessment of a single protein therapeutic, to the complete characterization of every possible protein including their modifications, which define the human proteoform. Given the controlling influence of protein modifications on their biological function, understanding how gene products manifest or respond to disease is most precisely achieved by characterization at the intact protein level. Top‐down mass spectrometry (MS) analysis of proteins entails unique challenges associated with processing whole proteins while maintaining their integrity throughout the processes of extraction, enrichment, purification, and fractionation. Recent advances in each of these critical front‐end preparation processes, including minimalistic workflows, have greatly expanded the capacity of MS for top‐down proteome analysis. Acknowledging the many contributions in MS technology and sample processing, the present review aims to highlight the diverse strategies that have forged a pathway for top‐down proteomics. We comprehensively discuss the evolution of front‐end workflows that today facilitate optimal characterization of proteoform‐driven biology, including a brief description of the clinical applications that have motivated these impactful contributions. [ABSTRACT FROM AUTHOR]

A new stability indicating reverse phase HPLC method has been developed and validated as per International Conference on Harmonization guidelines for the determination of sacubitril‐valsartan premix stereoisomers, namely, (2R)‐valsartan, (2S,4S)‐sacubitril, (2R,4S)‐sacubitril, and (2R,4R)‐sacubitril. Primarily, stability indicating separation study was done on reverse phase LC conditions; it was described by peak homogeneity of sacubitril–valsartan and its stereoisomers. Cellulose tris(4‐methylbenzoate) packing column Chiralcel OJ‐RH(150 mm × 4.6 mm), 5 μm provided better resolution than those of amylose based stationary phase's. Resolution between two arbitrary adjacent analyte was found to be more than 2.0 with 0.1% trifluoroacetic acid in water as mobile phase‐A and mobile phase‐B consisting of acetonitrile, methanol, and trifluoroacetic acid (90:10:0.1, v/v/v). Gradient elution was performed at a flow rate of 1.0 ml/min, column temperature 20°C, injection volume 10 μl, UV detection at 254 nm and run time was 52 min. The detector response linearity of stereoisomers found to be linear (R2 ≥ 0.9998), limit of detection (0.290 μg/ml, 0.122 μg/ml, 0.123 μg/ml, and 0.124 μg/ml), and limit of quantification (0.878 μg/ml, 0.370 μg/ml, 0.373 μg/ml, and 0.375 μg/ml), respectively. Percentage recovery was found to be 98–105. Finally, the proposed method is user friendly and can be used in bulk drugs analysis. [ABSTRACT FROM AUTHOR]

Summary: Inhibition of dipeptidyl peptidase IV (DPP‐IV) was considered to be a crucial target for type 2 diabetes, and food‐derived peptides were superior source of DPP‐IV inhibitory peptides. The purpose of this investigation was to identify inhibitory peptides from salmon skin collagen using simulated digestion combined with Caco‐2 cell monolayer membrane model. The analysis in silico showed that TKLPAVF and YLNF were potential inhibitory peptides. Determination of the inhibition activity showed that the IC50 values of TKLPVAF and YLNF were 242.10 ± 3.40 and 146.90 ± 4.40 µm, respectively. Molecular docking results showed that seven hydrogen bonds were formed between YLNF and key residues of DPP‐IV. YLNF may be considered a novel DPP‐IV inhibitory peptide. In addition, YLNF could be transported by Caco‐2 cell monolayer membrane in intact, and the apparent permeability coefficient value was (3.54 ± 0.34) × 10‐6 cm s−1 at 5 mm. [ABSTRACT FROM AUTHOR]

Reports on a study in which gonadotropin (GTH) was purified from the pituitaries of the Pacific chinook salmon using a combination of stepwise ethanol precipitation and concanavalin-A affinity chromatography. Reverse-phase high-performance liquid chromatography; Screening of an enriched cDNA library for the β-GTH genes using two synthetic oligonucleotides; Effect of testosterone implantation on pituitary PTH and β-GTH mRNA; Corresponding increase in both the pituitary GTH and mRNA levels.

With metabolism being one of the main routes of drug elimination from the body (accounting for removal of around 75% of known drugs), it is crucial to understand and study metabolic stability of drug candidates. Metabolically unstable compounds are uncomfortable to administer (requiring repetitive dosage during therapy), while overly stable drugs increase risk of adverse drug reactions. Additionally, biotransformation reactions can lead to formation of toxic or pharmacologically active metabolites (either less‐active than parent drug, or even with different action). There were numerous approaches in estimating metabolic stability, including in vitro, in vivo, in silico, and high‐throughput screening to name a few. This review aims at describing separation techniques used in in vitro metabolic stability estimation, as well as chemometric techniques allowing for creation of predictive models which enable high‐throughput screening approach for estimation of metabolic stability. With a very low rate of drug approval, it is important to understand in silico methods that aim at supporting classical in vitro approach. Predictive models that allow assessment of certain biological properties of drug candidates allow for cutting not only cost, but also time required to synthesize compounds predicted to be unstable or inactive by in silico models. [ABSTRACT FROM AUTHOR]

Apohemoglobin (apoHb) is a dimeric globular protein with two vacant heme‐binding pockets that can bind heme or other hydrophobic ligands. Purification of apoHb is based on partial hemoglobin (Hb) unfolding to facilitate heme extraction into an organic solvent. However, current production methods are time consuming, difficult to scale up, and use highly flammable and toxic solvents. In this study, a novel and scalable apoHb production method was developed using an acidified ethanol solution to extract the hydrophobic heme ligand into solution and tangential flow filtration to separate heme from the resultant apoprotein. Total protein and active protein yields were >95% and ~75%, respectively, with <1% residual heme in apoHb preparations and >99% purity from sodium dodecyl sulfate–polyacrylamide gel electrophoresis analysis. Virtually no loss of apoHb activity was detected at 4°C, −80°C, and in lyophilized form during long term storage. Structurally, size exclusion chromatography (SEC) and circular dichroism indicated that apoHb was dimeric with a ~25% reduction of helical content compared to Hb. Furthermore, mass spectroscopy and reverse‐phase chromatography indicated that the mass of the α and β subunits were virtually identical to the theoretical mass of these subunits in Hb and had no detectable oxidative modifications upon heme removal from Hb. SEC confirmed that apoHb bound to haptoglobin at a similar ratio to that of native Hb. Finally, reconstituted Hb (rHb) was processed via a hemichrome removal method to isolate functional rHb for biophysical characterization in which the O2 equilibrium curve, O2 dissociation, and CO association kinetics of rHb were virtually identical to native Hb. Overall, this study describes a novel and improved method to produce apoHb, as well as presents a comprehensive biochemical analysis of apoHb and rHb. [ABSTRACT FROM AUTHOR]

The venom produced by snakes contains complex mixtures of pharmacologically active proteins and peptides which play a crucial role in the pathophysiology of snakebite diseases. The deep understanding of venom proteomes can help to improve the treatment of this "neglected tropical disease" (as expressed by the World Health Organization [WHO]) and to develop new drugs. The most widely used technique for venom analysis is liquid chromatography/tandem mass spectrometry (LC/MS/MS)‐based bottom‐up (BU) proteomics. Considering the fact that multiple multi‐locus gene families encode snake venom proteins, the major challenge for the BU proteomics is the limited sequence coverage and also the "protein inference problem" which result in a loss of information for the identification and characterization of toxin proteoforms (genetic variation, alternative mRNA splicing, single nucleotide polymorphism [SNP] and post‐translational modifications [PTMs]). In contrast, intact protein measurements with top‐down (TD) MS strategies cover almost complete protein sequences, and prove the ability to identify venom proteoforms and to localize their modifications and sequence variations. [ABSTRACT FROM AUTHOR]

The single radial immunodiffusion assay has been the accepted method for determining the potency of inactivated influenza vaccines since 1978. The worldwide adoption of this assay for vaccine standardisation was facilitated through collaborative studies that demonstrated a high level of reproducibility and its applicability to the different types of influenza vaccine being produced at that time. Clinical evidence indicated the relevance of SRID as a potency assay. Unique features of the SRID assay are likely responsible for its longevity even as newer technologies for vaccine characterisation have been developed and refined. Nevertheless, there are significant limitations to the SRID assay that indicate the need for improvement, and there has been a substantial amount of work undertaken in recent years to develop and evaluate alternative potency assays, including collaborative studies involving research laboratories, regulatory agencies and vaccine manufacturers. Here, we provide an overview of the history of inactivated influenza vaccine potency testing, the current state of alternative assay development and the some of the major challenges to be overcome before implementation of new assays for potency determination. [ABSTRACT FROM AUTHOR]

A protocol for the microwave-assisted Heck coupling reaction of C-aryl glycosides and styrenes has been developed for the synthesis of mono- and bis( C-glycoside) stilbenes. This method exclusively provides C-glycoside trans-stilbenes in good yields. The Pd-catalyzed Heck coupling reaction was successfully applied to various functionalized C-glycosyl aryl iodides and various substituted styrenes to deliver several C-glycoside trans-stilbenes with high selectivity. The obtained C-glycosyl trans-stilbenes were also examined for human SGLT-2 inhibitory activity. [ABSTRACT FROM AUTHOR]

The pressures to efficiently produce complex biopharmaceuticals at reduced costs are driving the development of novel techniques, such as in downstream processing with straight-through processing (STP). This method involves directly and sequentially purifying a particular target with minimal holding steps. This work developed and compared six different 3-step STP strategies, combining membrane adsorbers, monoliths, and resins, to purify a large, complex, and labile glycoprotein from Chinese hamster ovary cell culture supernatant. The best performing pathway was cation exchange chromatography to hydrophobic interaction chromatography to affinity chromatography with an overall product recovery of up to 88% across the process and significant clearance of DNA and protein impurities. This work establishes a platform and considerations for the development of STP of biopharmaceutical products and highlights its suitability for integration with single-use technologies and continuous production methods. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:931-940, 2017 [ABSTRACT FROM AUTHOR]

Milk is a wholesome nutritious dairy product and is consumed by a majority of the population worldwide for drinking as such, as well as via dairy products. However, the practice of adulteration of milk invariably reduces its quality and may introduce hazardous substances into the dairy supply chain jeopardising consumers' health. Various instances of adulteration of milk have been reported globally, wherein substances such as extraneous water, foreign proteins, whey proteins, melamine and urea, vegetable or animal fats, plus many minor constituents of milk fat have been added as potential adulterants in milk and milk products. This review focusses on the different methods of detection of these adulterants in milk using techniques such as DSC, RP- HPLC, LC- GC, HPTLC, immunoassays: CE, ELISA, FAMPST, FTIR, NIR spectroscopy, PAGE, IEF, DNA-based methods and MALDI- MS that have been developed and employed for the last 25 years. The combination of advanced IR spectroscopy and chemometrics provides a powerful tool for quality and authenticity analysis of milk. An electronic tongue is an easy and economic tool for the detection of caprine milk adulterations with bovine milk. Biosensors having the ability to furnish real-time signals have been developed for the detection of urea in milk. An attempt has been made to give a clear understanding of the most suitable methods for the determination of various sources of adulteration. [ABSTRACT FROM AUTHOR]

Dopamine (DA) replacement therapy with L-DOPA continues to be the primary treatment of Parkinson's disease; however, long-term therapy is accompanied by L-DOPA-induced dyskinesias (LID). Several experimental and clinical studies have established that Propranolol, a b-adrenergic receptor antagonist, reduces LID without affecting L-DOPA's efficacy. However, the exact mechanisms underlying these effects remain to be elucidated. The aim of this study was to evaluate the anti-dyskinetic profile of Propranolol against a panel of DA replacement strategies, as well as elucidate the underlying neurochemical mechanisms. Results indicated that Propranolol, in a dose-dependent manner, reduced LID, without affecting motor performance. Propranolol failed to alter dyskinesia produced by the D1 receptor agonist, SKF81297 (0.08 mg/kg, sc), or the D2 receptor agonist, Quinpirole (0.05 mg/kg, sc). These findings suggested a pre-synaptic mechanism for Propranolol's anti-dyskinetic effects, possibly through modulating L-DOPA-mediated DA efflux. To evaluate this possibility, microdialysis studies were carried out in the DA-lesioned striatum of dyskinetic rats and results indicated that co-administration of Propranolol (20 mg/kg, ip) was able to attenuate L-DOPA- (6 mg/kg, sc) induced DA efflux. Therefore, Propranolol's anti-dyskinetic properties appear to be mediated via attenuation of L-DOPA-induced extraphysiological efflux of DA. [ABSTRACT FROM AUTHOR]

Sugar fatty acid nonionic surfactants have attracted great attention due to their good biodegradability, biocompatibility, and bio-based characteristics. Regioselective sugar acylation is difficult to control for chemical reactions. The immiscible nature between hydrophilic sugars and hydrophobic fatty acids also negatively affects the reaction efficiency. In the present study, a group of sugar fatty acid nonionic surfactants, ethyl di-rhamnolipids, was synthesized. Di-rhamnolipids were isolated from a Pseudomonas aeruginosa fermentation broth containing a rhamnolipid mixture with about 64 % di-rhamnolipids, and then purified by silica gel chromatography. Di-rhamnolipids were successfully ethylated at 0 °C for 24 h, confirmed by HPLC-MS and H-NMR analyses. Preliminary emulsification test indicated that ethyl di-rhamnolipids were a potential class of useful sugar fatty acid nonionic surfactants. The synthesis process was mild, did not require regioselective sugar acylation, and offered a new way of developing novel sugar fatty acid nonionic surfactants. [ABSTRACT FROM AUTHOR]