A5004166831- Mercury impact and mitigation studies
- Nitric Oxide and Endothelin Effects
- Analytical chemistry methods development
- Tea Polyphenols and Effects
- Chromium effects and bioremediation
- Diet, Metabolism, and Disease
- Genomics and Phylogenetic Studies
- Microbial Natural Products and Biosynthesis
- Enzyme Production and Characterization
- Marine Sponges and Natural Products
- Hemoglobin structure and function
- Ginkgo biloba and Cashew Applications
- Biofuel production and bioconversion
- Amino Acid Enzymes and Metabolism
- Studies on Chitinases and Chitosanases
- Aquaculture disease management and microbiota
- Bacterial biofilms and quorum sensing
- Heavy metals in environment
- Advanced Nanomaterials in Catalysis
- Environmental Toxicology and Ecotoxicology
- Microbial bioremediation and biosurfactants
- Electrochemical sensors and biosensors
- Ginseng Biological Effects and Applications
- Analytical Chemistry and Sensors
- Metal-Catalyzed Oxygenation Mechanisms
Jadavpur University
2013-2023
Yahoo (United Kingdom)
2015
University of Calcutta
1990-2006
Cleveland Clinic
1996-2004
Cleveland Clinic Lerner College of Medicine
1998
Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques
1998
Université Paris Cité
1998
Centre National de la Recherche Scientifique
1998
Scripps Research Institute
1997
The nitric oxide synthase oxygenase domain (NOS ox ) oxidizes arginine to synthesize the cellular signal and defensive cytotoxin (NO). Crystal structures determined for cytokine-inducible NOS reveal an unusual fold heme environment stabilization of activated oxygen intermediates key catalysis. A winged β sheet engenders a curved α-β resembling baseball catcher's mitt with clasped in palm. location exposed hydrophobic residues results mutational analysis place dimer interface adjacent...
Three nitric-oxide synthase (NOS) isozymes play crucial, but distinct, roles in neurotransmission, vascular homeostasis, and host defense, by catalyzing Ca(2+)/calmodulin-triggered NO synthesis. Here, we address current questions regarding NOS activity regulation combining mutagenesis biochemistry with crystal structure determination of a fully assembled, electron-supplying, neuronal reductase dimer. By integrating these results, structurally elucidate the unique mechanisms for...
Nitric oxide synthases (NOS) are hemeproteins that catalyze oxidation of L-arginine to nitric (NO) and citrulline. The NOS heme iron is expected participate in oxygen activation during catalysis, but its interactions with O2 not characterized. We utilized the heme-containing oxygenase domain neuronal (nNOSoxy) stopped-flow methods study formation autooxidative decomposition nNOSoxy oxygenated complex at 10 degrees C. Mixing ferrous air-saturated buffer generated a transient species...
Endothelial nitric-oxide synthase (eNOS) is targeted to caveoli through interaction with caveolin-1 (cav-1). cav-1 binding a consensus site in the eNOS oxygenase domain proposed antagonize calmodulin (CaM) and thereby inhibit nitric oxide (NO) synthesis. To study mechanism, we examined how scaffolding peptide (amino acids 82–101; cav-1P) would affect NO synthesis, NADPH oxidation, cytochrome <i>c</i> reduction, ferricyanide reduction by full-length or its isolated reductase domains. Cav-1P...
Rat neuronal NO synthase (nNOS) is comprised of a flavin-containing reductase domain and heme-containing oxygenase domain. Calmodulin binding to nNOS increases the rate electron transfer from NADPH into its flavins, triggers flavins heme, activates synthesis, reduction artificial acceptors such as cytochrome c. To investigate what role plays in calmodulin's activation these functions, we overexpressed form (amino acids 724-1429) yeast Pichia pastoris that for first time exhibits complete...
A few members of the family Acetobacteraceae are cellulose-producers, while only six fix nitrogen. Bacterial strain RG3 T , isolated from Kombucha tea, displays both these characteristics. high bootstrap value in 16S rRNA gene sequence-based phylogenetic analysis supported position this within genus Gluconacetobacter with hansenii LMG 1527 as its nearest neighbour (99.1 % sequence similarity). It could utilize ethanol, fructose, arabinose, glycerol, sorbitol and mannitol, but not galactose...
Kombucha, a fermented tea (KT) is claimed to possess many beneficial properties. Recent studies have suggested that KT prevents paracetamol and carbon tetrachloride-induced hepatotoxicity. We investigated the role of was against tertiary butyl hydroperoxide (TBHP) induced cytotoxicity cell death in murine hepatocytes. TBHP well known reactive oxygen species (ROS) inducer, it induces oxidative stress organ pathophysiology. In our experiments, caused reduction viability, enhanced membrane...
The present study was undertaken to determine the mechanism of antibacterial activity a polyphenolic fraction, composed mainly catechin and isorhamnetin, previously isolated from Kombucha, 14-day fermented beverage sugared black tea, against enteropathogen Vibrio cholerae N16961. Bacterial growth found be seriously impaired by fraction in dose-dependent manner. Scanning Electron Microscopy demonstrated morphological alterations bacterial cells when exposed concentration-dependent...
The four nitrogen-fixing bacteria so far described in the family Acetobacteraceae belong to genera Gluconacetobacter and Acetobacter . Nitrogen-fixing bacterial strain RG1 T was isolated from Kombucha tea and, based on phylogenetic analysis of 16S rRNA gene sequence which is supported by a high bootstrap value, found genus Strain differed aceti , nearest member with similarity 98.2 %, type strains other species regard several characteristics growth features culture media, nitrogen-free...
The oxygenase domain of the mouse cytokine-inducible nitric-oxide synthase (iNOSox, amino acids 1−498) binds heme, tetrahydrobiopterin, and substrate Arg is responsible for catalyzing nitric oxide synthesis maintaining enzyme's active dimeric structure. To further understand iNOSox structure−function, we carried out alanine point mutagenesis on 15 conserved acidic residues located within a region (amino 352−473) that shares sequence homology with pterin-binding module in dihydrofolate...
Calmodulin (CaM) binding activates neuronal nitric-oxide synthase (nNOS) catalytic functions and also up-regulates electron transfer into its flavin heme centers. Here, we utilized seven tight CaM-troponin C chimeras, which variably activate nNOS NO synthesis to examine the relationship between CaM domain structure, activation of functions, control internal at two points within nNOS. Chimeras that were singly substituted with troponin domains 4, 3, 2, or 1 increasingly unable synthesis, but...
A histidine-based amphiphilic peptide (P) has been found to form an injectable transparent hydrogel in phosphate buffer solution over a pH range from 7.0 8.5 with inherent antibacterial property. It also formed water at = 6.7. The self-assembles into nanofibrillar network structure which is characterized by high-resolution transmission electron microscopy, field-emission scanning atomic force small-angle X-ray scattering, Fourier-transform infrared spectroscopy, and wide-angle powder...