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Colour of light modulates the appearance of displayed artifacts in exhibition. To understand the effect of light on appearance of paintings, few studies have experimented to establish a relation between pleasantness with the correlated colour temperature (CCT) of light. However, some studies have found that CCT has no significant effect on pleasant appearance of painting. Therefore, in this article, an experiment with a qualitative (questionnaire on semantic differential scale, N = 30) approach was designed to understand the effect of CCT on appearance of paintings exhibited under LED lights. The findings from the experimental result depict that the appearance of paintings changes due to different CCTs of LEDs having the same illuminance. In addition, the result reveals that for both mediums of paintings considered in this study, in comparison to warm white LED and artificial daylight LED, cool white LED has appeared to be more pleasant having moderately warm feelings to the viewers. [ABSTRACT FROM AUTHOR]

Summary Cerebral cavernous malformations (CCMs) are vascular defects of the CNS that arise from loss of integrity of the endothelial cells lining blood capillaries, causing leakage of blood into the brain [ 1 ]. This results in headaches, seizures, and/or hemorrhagic stroke, depending on the location of the lesion. CCM affects 0.5% of the population and follows an autosomal dominant inheritance pattern caused by mutations in one of the three genes: CCM1 (gene name KRIT1 ), CCM2 (also known as malcavernin or OSM ), and CCM3 (gene name PDCD10 ) [ 2, 3 ], with the earliest onset and most severe prognosis occurring in CCM3 patients [ 4 ]. The three CCM genes encode structurally distinct scaffold proteins that function in multiple complexes [ 5–9 ]. Using the C. elegans germline as a model of multicellular tube development, we show here that CCM-3 is enriched at the luminal membrane of the germline and the contractile ring of dividing cells in the embryo. Loss of ccm-3 results in defective RAB-11-mediated endocytic recycling, which in turn is necessary for gonadal lumen (rachis) formation, completion of cytokinesis, and localization of cell-surface receptors. CCM-3-mediated localization of anillin and non-muscle myosin to the lateral surfaces of germ cells is required for proper cytoskeletal organization, subsequent oocyte growth, and localization of polarity proteins. Biochemical analysis reveals conservation of the STRIPAK complex and distinct roles for GCK-1 (germinal center kinase III family protein) and striatin/CASH-1 in controlling the localization and function of CCM-3. Taken together, our data establish CCM-3 as a novel regulator of rachis lumenization and polarity establishment during embryogenesis. [ABSTRACT FROM AUTHOR]

Significance: Reactive oxygen species (ROS) are produced as natural byproducts of metabolism and respiration. While physiological levels of ROS are required for vital cellular functions (e.g., development and proliferation), a living organism is faced with constant challenges due to accumulation or overproduction of ROS throughout its life. The life cycle of Leishmania parasite has led it to confront the highly oxidizing environment in the macrophage phagosomes, necessitating ROS homeostasis and signaling as key strategies for successful survival and pathogenicity. Recent Advances: Ascorbate peroxidase from Leishmania major (LmAPX) is the only heme peroxidase identified so far in Leishmania. Structural analysis and functional characterization of LmAPX have yielded interesting and novel insight on this enzyme. The protein has been found to be a hybrid of cytochrome c peroxidase and ascorbate peroxidase. This enzyme is colocalized with cytochrome c in the inner mitochondrial membrane facing the intermembrane space and shows higher activity toward cytochrome c oxidation. Critical Issues: Overexpression of LmAPX in L. major cells confers tolerance to oxidative stress-mediated cardiolipin oxidation and consequently protects cells from extensive protein damage. LmAPX-/- mutants show higher intracellular hydrogen peroxide (H2O2), which might signal for cellular transformation from noninfective procyclic to infective metacyclic form and ultimately apoptosis. Future Directions: Manipulation of LmAPX expression has significantly added to the present understanding of the parasite's defense network against oxidative damage caused by H2O2. The future investigations will address more exactly the signaling pathways involved in redox homeostasis. [ABSTRACT FROM AUTHOR]

Abstract: The endogenous cation in peroxidases may contribute to the type of heme coordination. Here a series of ferric and ferrous derivatives of wild-type Leishmania major peroxidase (LmP) and of engineered K+ site mutants of LmP, lacking potassium cation binding site, has been examined by electronic absorption spectroscopy at 25°C. Using UV–visible spectrophotometry, we show that the removal of K+ binding site causes substantial changes in spin states of both the ferric and ferrous forms. The spectral changes are interpreted to be, most likely, due to the formation of a bis-histidine coordination structure in both the ferric and ferrous oxidation states at neutral pH 7.0. Stopped flow spectrophotometric techniques revealed that characteristics of Compound I were not observed in the K+ site double mutants in the presence of H2O2. Similarly electron donor oxidation rate was two orders less for the K+ site double mutants compared to the wild type. These data show that K+ functions in preserving the protein structure in the heme surroundings as well as the spin state of the heme iron, in favor of the enzymatically active form of LmP. [Copyright &y& Elsevier]

In India, the cashew nut shelling (CNS) is an important task in all small-scale cashew nut processing industries. Workers engaged in CNS task commonly operate pedal-operated cashew nut sheller (CNSR) in awkward standing posture that can contribute to work-related musculoskeletal disorders (MSDs). However, investigations from an ergonomics perspective have barely been conducted in Indian small-scale cashew nut processing industries. Therefore, the present study aims to evaluate the postural workload in CNS task to propose an ergonomic design intervention in small-scale cashew nut processing industries. A combination of methods, including posture recording, postural assessment, interviews, questionnaire study, virtual prototyping, and digital human modeling and simulation, were used. Using the pedal-operated CNSR resulted in high-risk postures of MSDs. Based on these preliminary findings, a simple, improved, and adjustable hand-operated CNSR was designed and evaluated ergonomically. It was found that newly designed CNSR improved postures noticeably and provided comfort for workers. [ABSTRACT FROM AUTHOR]

Abstract: The active site architecture of Leishmania major peroxidase (LmP) is very similar with both cytochrome c peroxidase and ascorbate peroxidase. We utilized point mutagenesis to investigate if the conserved proximal methionine residues (Met248 and Met249) in LmP help in controlling catalysis. Steady-state kinetics of methionine mutants shows that ferrocytochrome c oxidation is <2% of wild type levels without affecting the second order rate constant of first phase of Compound I formation, while the activity toward a small molecule substrate, guaiacol or iodide, increases. Our diode array stopped-flow spectral studies show that the porphyrin π-cation radical of Compound I in mutant LmP is more stable than wild type enzyme. These results suggest that the electronegative sulfur atoms of the proximal pocket are critical factors for controlling the location of a stable Compound I radical in heme peroxidases and are important in the oxidation of ferrocytochrome c. [Copyright &y& Elsevier]

Numerous reports have shown that mitochondrial dysfunctions play a major role in apoptosis of Leishmania parasites, but the endoplasmic reticulum (ER) stress-induced apoptosis in Leishmania remains largely unknown. In this study, we investigate ER stress-induced apoptotic pathways in Leishmania major using tunicamycin as an ER stress inducer. ER stress activates the expression of ER-localized chaperone protein BIP/GRP78 (binding protein/identical to the 78-kDa glucose-regulated protein) with concomitant generation of intracellular reactive oxygen species. Upon exposure to ER stress, the elevation of cytosolic Ca2+ level is observed due to release of Ca2+ from internal stores. Increase in cytosolic Ca2+ causes mitochondrial membrane potential depolarization and ATP loss as ablation of Ca2+ by blocking voltage-gated cation channels with verapamil preserves mitochondrial membrane potential and cellular ATP content. Furthermore, ER stress-induced reactive oxygen species (ROS)-dependent release of cytochrome c and endonuclease G from mitochondria to cytosol and subsequent translocation of endonuclease G to nucleus are observed. Inhibition of caspase-like proteases with the caspase inhibitor benzyloxycarbonyl-VAD-fluoromethyl ketone or metacaspase inhibitor antipain does not prevent nuclear DNA fragmentation and phosphatidylserine exposure. Conversely, significant protection in tunicamycin-induced DNA degradation and phosphatidylserme exposure was achieved by either pretreatment of antioxidants (N-acetyl-L-cysteine, GSH, and L-cysteine), chemical chaperone (4-phenylbutyric acid), or addition of Ca2+ chelator (1,2-bis(2-aminophenoxy)ethane-N,JV,N,N-tetraacetic acidacetoxymethyl ester). Taken together, these data strongly demonstrate that ER stress-induced apoptosis in L. major is dependent on ROS and Ca2+-induced mitochondrial toxicity but independent of caspase-like proteases. [ABSTRACT FROM AUTHOR]

Background: Peroxidase represents a heterogeneous group of distinct enzyme family that plays extremely diverse biological functions. Ascorbate peroxidase from Leishmania major (LmAPX) has been shown to be central to the redox defense system of Leishmania. To investigate further its exact physiological role in Leishmania, we attempted to create LmAPX -knockout mutants by gene replacement in L. major strains. Methodology/Principal Findings: The null mutant cell culture contains a higher percentage of metacyclic and apoptotic cells compared to both wild type and LmAPX overexpressing cells. Flowcytometric analysis reveals the presence of a higher concentration of intracellular H2O2, indicative of increased oxidative stress in parasites lacking LmAPX. IC50 value for exogenously added H2O2 shows that deletion of LmAPX in L. major renders the cell more susceptible to H2O2. Real time PCR studies demonstrate an elevated mRNA level of non-selenium glutathione peroxidase in LmAPX null mutant cell line, suggesting that these enzymes were induced to compensate the LmAPX enzyme. The null mutant cells exhibit hypervirulence after infection with macrophages as well as inoculation into BALB/c mice; in contrast, overexpressing cells show avirulence. Conclusions/Significance: Collectively, these data provide strong evidence that LmAPX is an important factor for controlling parasite differentiation and survival within macrophages. [ABSTRACT FROM AUTHOR]

Abstract: Architecture of hemoprotein is solely responsible for different nature of heme coordination. Here we report that substitution of the acidic surface residue Glu226 to Ala in ascorbate peroxidase from Leishmania major alters the 5 coordinate high spin (5cHS) to a 6 coordinate low spin (6cLS) form at pH 7.5. Using UV–visible spectrophotometry, we show that the sixth ligand of heme in Glu226Ala at pH 7.5 is hydroxo. When the pH is decreased to 5.5, a new species of Glu226Ala appeared that had a spectrum characteristic of a 6cHS derivative. Stopped flow spectrophotometric techniques revealed that characteristics of Compound I was not seen in the Glu226Ala in presence of H2O2. Similarly guaiacol, ascorbate and ferrocytochrome c oxidation rate was 103 orders less for the Glu226Ala mutants compared to the wild type. These data suggested that surface acidic residue Glu226 might play role in proper maintenance of active site conformation. [Copyright &y& Elsevier]

Abstract: Heme peroxidases are a class of multifunctional redox-active proteins found in all organisms. We recently cloned, expressed, and characterized an ascorbate peroxidase from Leishmania major (LmAPX) that was capable of detoxifying hydrogen peroxide. Localization studies using green fluorescent protein fusions revealed that LmAPX was localized within the mitochondria by its N-terminal signal sequence. Subcellular fractionation analysis of the cell homogenate by the Percoll density-gradient method and subsequent Western blot analysis with anti-LmAPX antibody further confirmed the mitochondrial localization of mature LmAPX. Submitochondrial fractionation analysis showed that the mature enzyme (∼3.6 kDa shorter than the theoretical value of the whole gene) was present in the intermembrane space side of the inner membrane. Moreover, expression of the LmAPX gene was increased by treatment with exogenous H2O2, indicating that LmAPX was induced by oxidative stress. To investigate the biological role of LmAPX we generated Leishmania cells overexpressing LmAPX in the mitochondria. Flow-cytometric analysis, thin-layer chromatography, and IC50 measurements suggested that overexpression of LmAPX caused depletion of the mitochondrial ROS burden and conferred a protection against mitochondrial cardiolipin oxidation and increased tolerance to H2O2. These results suggest that the single-copy LmAPX gene plays a protective role against oxidative damage. [Copyright &y& Elsevier]

Abstract: Ascorbate peroxidase from L. Major (LmAPX) is a functional hybrid between cytochrome c peroxidase (CCP) and ascorbate peroxidase (APX). We utilized point mutagenesis to investigate if a conserved proximal tryptophan residue (Trp208) among Class I peroxidase helps in controlling catalysis. The mutant W208F enzyme had no effect on both apparent dissociation constant of the enzyme–cytochrome c complex and K m value for cytochrome c indicating that cytochrome c binding affinity to the enzyme did not alter after mutation. Surprisingly, the mutant was 1000 times less active than the wild type in cytochrome c oxidation without affecting the second order rate constant of compound I formation. Our diode array stopped-flow spectral studies showed that the substrate unbound wild type enzyme reacts with H2O2 to form compound I (compound II type spectrum), which was quite different from that of compound I in W208F mutant as well as horseradish peroxidase (HRP). The spectrum of the compound I in wild type LmAPX showed a red shift from 409 nm to 420 nm with equal intensity, which was broadly similar to those of known Trp radical. In case of compound I for W208F mutant, the peak in the Soret region was decreased in heme intensity at 409 nm and was not shifted to 420 nm suggesting this type of spectrum was similar to that of the known porphyrin π-cation radical. In case of an enzyme–H2O2–ascorbate system, the kinetic for formation and decay of compound I and II of a mutant enzyme was almost identical to that of a wild type enzyme. Thus, the results of cytochrome c binding, compound I formation rate and activity assay suggested that Trp208 in LmAPX was essential for electron transfer from cytochrome c to heme ferryl but was not indispensable for ascorbate or guaiacol oxidation. [Copyright &y& Elsevier]

Abstract: Nitric oxide (NO) is an important cellular mediator of tissue repair. It is produced in macrophages by the enzyme inducible nitric oxide synthase (iNOS) during wound healing. An aqueous extract of human placenta used as wound healer, has been investigated in terms of induction of NO by mouse peritoneal macrophages as well as human monocyte derived macrophages. NO production was estimated in macrophages culture supernatants. Incubation of 0.1 to 20 mg/ml of placental extract with 2×106 cells in vitro produced 10 to 100 μM of nitrite (n =4) in a dose dependent manner suggesting production of NO. With increase of NO production, NADPH present in the applied extract decreased proportionately. Application of L-NG monomethyl arginine (L-NMMA), an NO synthase (NOS) inhibitor, reduced the production of NO at the basal level. Dose dependent release of IFN-γ with respect to placental extract by the mouse macrophages was observed. It has been observed that human monocytes derived macrophages also produced significant amount of NO by induction of the extract. Similar induction of NO by placental extract in presence and absence of polymyxin B suggested that this property is not likely to be mediated by the endotoxin/LPS. [Copyright &y& Elsevier]

Macromolecular complexes are essential to conserved biological processes, but their prevalence across animals is unclear. By combining extensive biochemical fractionation with quantitative mass spectrometry, here we directly examined the composition of soluble multiprotein complexes among diverse metazoan models. Using an integrative approach, we generated a draft conservation map consisting of more than one million putative high-confidence co-complex interactions for species with fully sequenced genomes that encompasses functional modules present broadly across all extant animals. Clustering reveals a spectrum of conservation, ranging from ancient eukaryotic assemblies that have probably served cellular housekeeping roles for at least one billion years, ancestral complexes that have accrued contemporary components, and rarer metazoan innovations linked to multicellularity. We validated these projections by independent co-fractionation experiments in evolutionarily distant species, affinity purification and functional analyses. The comprehensiveness, centrality and modularity of these reconstructed interactomes reflect their fundamental mechanistic importance and adaptive value to animal cell systems. [ABSTRACT FROM AUTHOR]

In this manuscript we demonstrate that a modification principally directed toward the improvement of the aqueous solubility (i.e., introduction a P3 pyridine N-oxide) of the previous lead compound afforded a new series of potent orally bioavailable P1 N-benzylamide thrombin inhibitors. An expedited investigation of the P1 SAR with respect to oral bioavailability, plasma half-life, and human liver microsome stability revealed 5 as the best candidate for advanced evaluation. [Copyright &y& Elsevier]