University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

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Physiology

International Journal of Laboratory Hematology

Cord and peripheral blood erythrocyte analysis by scanning electron microscopy and flow cytometry

Inhalation toxicology 33 (6-8)

Oxidative degradation perturbs physico-chemical properties of hemoglobin in cigarette smokers: a threat to different biomolecules

Etoricoxib, widely used for the treatment of osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, and related conditions has ample affinity to bind with globular proteins. Here, the molecular interaction between purified human hemoglobin (HHb), a major heme protein and etoricoxib, a cyclooxygenase-2 inhibitor was studied by various spectroscopic, calorimetric, and molecular modeling techniques. The binding affected hypochromic changes in the Soret band of hemoglobin (Hb) and induced remarkable quenching of the intrinsic fluorescence property of protein molecules. Synchronous fluorescence studies revealed alterations in tryptophan (Trp) and tyrosine (Tyr) microenvironments of HHb molecule in presence of etoricoxib. Flouremetric and isothermal titration calorimetric studies suggested two binding sites in HHb for etoricoxib at three different temperatures (298.15, 303.15, and 310.15 K). Negative values of Gibbs energy change (ΔG0) and enthalpy change (ΔH0) strongly suggest that it is spontaneous and exothermic reaction, mainly stabilized by hydrogen bonding as evidenced by sucrose binding assay. These findings support our in silico molecular docking study, which specified the binding site and the non-covalent interactions involved in the association. Moreover, the interaction impacts on structural integrity and functional aspects of HHb as confirmed by decreased α helicity, increased free iron release, increased rate of co-oxidation, and decreased rate of esterase activity. Overall, these studies conclude that etoricoxib leads to a remarkable alteration in the conformational aspects of binding to HHb. Communicated by Ramaswamy H. Sarma. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.

GENERAL

Journal of Biomolecular Structure and Dynamics

Exploring the binding dynamics of etoricoxib with human hemoglobin: A spectroscopic, calorimetric, and molecular modeling approach

IN VITRO ANTILEISHMANIAL ACTIVITY OF DIPLAZIUM ESCULENTUM

Ibuprofen, used for the treatment of acute and chronic pain, osteoarthritis, rheumatoid arthritis, and related conditions has ample affinity to globular proteins. Here we have explored this fundamental study pertaining to the interaction of ibuprofen with human hemoglobin (HHb), using multispectroscopic, calorimetric, and molecular modeling techniques to gain insights into molecular aspects of binding mechanism. Ibuprofen-induced graded decrease in absorption spectra indicates protein disruption along with sedimentation of HHb particle. Red shifting of absorption peak at 195 nm indicates alteration in the secondary structure of HHb upon interaction with ibuprofen. Flouremetric and isothermal titration calorimetric (ITC) studies suggested one binding site in HHb for ibuprofen at 298.15 K. However, with increase in temperature, ITC revealed increasing number of binding sites. The negative values of Gibbs energy change (ΔG 0 ) and enthalpy change (ΔH 0 ) along with positive value of entropy change (ΔS 0 ) strongly suggest that it is entropy-driven spontaneous exothermic reaction. Moreover, hydrophobic interaction, hydrogen bonding, and π–π interaction play major role in this binding process as evidenced from ANS (8-anilino-1-napthalenesulphonic acid), sucrose binding, and molecular modeling studies. The interaction impacts on structural integrity and functional aspects of HHb as confirmed by CD spectroscopy, increased free iron release, increased rate of co-oxidation and decreased rate of esterase activity. These findings suggest us to conclude that ibuprofen upon interaction perturbs both structural and functional aspects of HHb. © 2017 Informa UK Limited, trading as Taylor & Francis Group.

Binding of ibuprofen to human hemoglobin: Elucidation of their molecular recognition by spectroscopy, calorimetry, and molecular modeling techniques

Linezolid, one of the reserve antibiotic of oxazolidinone class has wide range of antimicrobial activity. Here we have conducted a fundamental study concerning the dynamics of its interaction with bovine serum albumin (BSA), and the post binding modification of the later by employing different spectroscopic (absorption, fluorescence and circular dichroism (CD) spectroscopy) and molecular docking tools. Gradual quenching of the tryptophan (Trp) fluorescence upon addition of linezolid to BSA confirms their interaction. Analysis of fluorescence quenching at different temperature indicates that the interaction is made by static complex formation and the BSA has one binding site for the drug. The negative Gibbs energy change (ΔG 0 ), and positive values of enthalpy change (ΔH 0 ) and entropy change (ΔS 0 ) strongly suggest that it is an entropy driven spontaneous and endothermic reaction. The reaction involves hydrophobic pocket of the protein, which is further stabilized by hydrogen bonding and electrostatic interactions as evidenced from 8-anilino-1-napthalene sulfonic acid, sucrose and NaCl binding studies. These findings also support the molecular docking study using AutoDock 4.2. The influence of this interaction on the secondary structure of the protein is negligible as evidenced by CD spectroscopy. So, from these findings, we conclude that linezolid interacts with BSA in 1:1 ratio through hydrophobic, hydrogen bonding and ionic interactions, and this may not affect the secondary structure of the protein. © 2017 Informa UK Limited, trading as Taylor & Francis Group.

Underlying molecular interaction of bovine serum albumin and linezolid: a biophysical outlook

Erythrocytes in cigarette smokers are prone to oxidative damage. Here, we sought to elucidate the facts behind modifications and possible defense system developed in erythrocyte of cigarette smokers. We observed significant increase in stomatocytes and spherocytes, and osmotic fragility of erythrocyte, along with reduced level of protein thiol and increased fluorescence anisotropy in isolated membrane. Denaturing gel electrophoresis indicated alterations in band 3, band 4.2 and band 4.5. Among those, Glut 1 (i.e. band 4.5), which transports glucose (insulin independent) and dehydroascorbate (DHA), was selectively chosen for its long history in reducing reactive oxygen species (ROS). The increased Glut 1 level in smokers was confirmed by immunoblotting and immunocytochemistry. Furthermore, smokers showed significantly higher glucose uptake in whole blood. The intracellular (Ic) ROS (as indicated by 2′,7′-dichlorofluorescin) was significantly higher in smokers as evidenced by flow cytometric assay. Glucose and DHA alone or together significantly reduced IcROS at higher rate in smokers. However, in presence of Glut 1 specific blocker, phloretin, neither glucose nor DHA could reduce IcROS in both non-smokers and smokers. This confirms that Glut 1 by transporting glucose or DHA attenuates IcROS. Therefore, we conclude that erythrocytes, although altered morphologically, also develop a defense system by upregulating Glut 1 to combat with enhanced Ic oxidative insult in cigarette smokers. © 2017 Informa UK Limited, trading as Taylor & Francis Group.

Free Radical Research

Cigarette smokers develop altered erythrocyte membrane composition: an investigation unmasking the role of membrane bound integral protein GLUT 1

Acetaminophen, a widely used analgesic and antipyretic drug has ample affinity to bind globular proteins. Here, we have illustrated a substantive study pertaining to the interaction of acetaminophen with human hemoglobin (HHb). Different spectroscopic (absorption, fluorescence, and circular dichroism (CD) spectroscopy), calorimetric, and molecular docking techniques have been employed in this study. Acetaminophen-induced graded alterations in absorbance and fluorescence of HHb confirm their interaction. Analysis of fluorescence quenching at different temperature and data obtained from isothermal titration calorimetry indicate that the interaction is static and the HHb has one binding site for the drug. The negative values of Gibbs energy change (ΔG 0 ) and enthalpy changes (ΔH 0 ) and positive value of entropy change (ΔS 0 ) strongly suggest that it is entropy-driven spontaneous and exothermic reaction. The reaction involves hydrophobic pocket of the protein which is further stabilized by hydrogen bonding as evidenced from ANS and sucrose binding studies. These findings were also supported by molecular docking simulation study using AutoDock 4.2. The interaction influences structural integrity as well as functional properties of HHb as evidenced by CD spectroscopy, increased rate of co-oxidation and decreased esterase activity of HHb. So, from these findings, we may conclude that acetaminophen interacts with HHb through hydrophobic and hydrogen bonding, and the interaction perturbs the structural and functional properties of HHb. © 2016 Informa UK Limited, trading as Taylor & Francis Group.

Acetaminophen interacts with human hemoglobin: optical, physical and molecular modeling studies

Context: Increased levels of free radicals and various reactive species along with reduced antioxidant defence system are the major threat to erythrocyte in tobacco smokers. Thus, the hemoglobin (Hb) within the erythrocyte is very prone to oxidative damage. Earlier reports suggest that cigarette smoking is related with the glutathionylation and formation of adducts of Hb. Objective: We have highlighted the possible changes in secondary and tertiary structures of Hb in cigarette smokers and its physiological consequences. Material and method: Twenty smokers and 18 non-smokers, aged 25-35 years were volunteered in this study. We used flow cytometry for measuring intracellular reactive oxygen species (IcROS). The purified Hb was subjected to different spectrophotometric, fluoremetric and circular dichroic (CD) analysis. The hydrophobicity, thermal stability, heme release and oxidation of purified Hb were also studied. Result: We observed that the IcROS was also higher in cigarette smokers than non-smokers. The data of intrinsic fluorescence, synchronous fluorescence and tryptophan quenching studies showed that the microenvironments of β37 tryptophan and tyrosine residues of Hb were moved toward more hydrophobic region in cigarette smokers. Increased hydrophobicity and thermal stability furthermore indicated more compactness of smokers' hemoglobin. From CD spectra, we confirmed an overall modification of the secondary and tertiary structures of hemoglobin in smokers. Both auto-and co-oxidation rates of purified Hb were found to be higher in cigarette smokers. Discussion and conclusion: We conclude that the modified Hb in cigarette smokers may further enhance the oxidative insult within the cell. © 2015 Informa Healthcare USA, Inc. All rights reserved.

Inhalation Toxicology

Cigarette smokers develop structurally modified hemoglobin: A possible way of increasing oxidative stress

NorM, a putative efflux pump of Vibrio cholerae, is a member of the multidrug and toxic compound extrusion family of transporters. We demonstrate that NorM confers resistance to norfloxacin, ciprofloxacin, and ethidium bromide. Inactivation of norM rendered V. cholerae hypersensitive towards these fluoroquinolones. Multiple sequence alignment of members of its family identified several regions of high sequence conservation. The topology of NorM was determined using β-lactamase and chloramphenicol acetyltransferase fusions. The amino acid residues G184, K185, G 187, P189, E190, G192, and G 195 in the periplasmic loops and L381, R382, G383, Y384, K385, and D386 in the cytoplasmic loops, as well as all the acidic and cysteine residues of NorM, were mutated. Mutants G184V, G184W, K185I, P189S, E190K, and E190A lost the norfloxacin resistance-imparting phenotype characteristic of NorM. Mutants E124V, D155V, G187V, G187R, C196S, Y384H, Y384S, and Y384F exhibited partial resistance to norfloxacin. Mutants with replacements of G184 or G187 by A, K185 by R, and E190 by D retained the norfloxacin resistance phenotype of NorM. Analysis of the accumulation of norfloxacin in intact cells of Escherichia coli expressing NorM or its mutants in the presence or absence of carbonyl cyanide m-chlorophenylhydrazone supported the results obtained through susceptibility testing and argued in favor of NorM-mediated efflux as the determining factor in norfloxacin susceptibility in the genetically manipulated strains. Taken together, these results suggested that E124, D155, G184, K185, G 187, P189, E190, C196, and Y 384 are likely involved in NorM-dependent norfloxacin efflux. Except for D155, C196, and Y384, all of these residues are located in periplasmic loops. Copyright © 2006, American Society for Microbiology. All Rights Reserved.