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Parvez A, Ravikumar Y, Bisht R, Yun J, Wang Y, Chandrika SP, Zabed HM, Qi X. Functional and Structural Roles of the Dimer Interface in the Activity and Stability of Clostridium butyricum 1,3-Propanediol Oxidoreductase. ACS Synth Biol 2022; 11:1261-1271. [PMID: 35258945 DOI: 10.1021/acssynbio.1c00555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Biosynthesis of 1,3-propanediol (1,3-PD) by 1,3-propanediol oxidoreductase (PDOR) is often limited by the stability issues. To address this issue, the goal of the present study was to engineer the Clostridium butyricum PDOR dimeric interface. The interface exists between the chains and plays a role in the synthesis of 1,3-PD, which is hindered by the increased temperature and pH. Herein, we engineered PDOR by HotSpot Wizard 3.0 and molecular dynamics simulations, improving its thermal stability, pH tolerance, and catalytic properties with respect to the wild-type PDOR activity at 37 °C. Compared to the activity of the wild-type PDOR, the N298C mutant showed 0.5-fold greater activity at pH 8.0, while the P299E mutant showed significantly increased activity of over five fold at pH 4.0. Further structural comparisons between the wild-type and P299E mutant revealed that the extraordinary stability of the P299E mutant could be due to the formation of additional hydrogen bonds and salt bridges. The N298C mutant also exhibits thermal stability at a broad range of temperature at pH 8 with respect to wild-type PDOR and other mutants. The molecular dynamics simulations revealed that stability profiles of P299E mutants at pH 4.0 are attributed to identical root mean square deviation values and stable conformations in the motif region present in the dimer interface of the enzyme. These findings suggest that the dimer interface motifs are essential for the compactness and stability of the PDOR enzyme; therefore, engineering the PDOR using a structure-guided approach could aid in improving its activity and stability under various physiological conditions (pH and temperature).
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Affiliation(s)
- Amreesh Parvez
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, Jiangsu, China
| | - Yuvaraj Ravikumar
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, Jiangsu, China
| | - Renu Bisht
- Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi 110021, India
| | - Junhua Yun
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, Jiangsu, China
| | - Yang Wang
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, Jiangsu, China
| | - Sabapathy Poorna Chandrika
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, Jiangsu, China
| | - Hossain M. Zabed
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, Jiangsu, China
| | - Xianghui Qi
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, Jiangsu, China
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Sharma R, Bisht R, Tikka SK, Bhute AR, Bastia BK. COVID-19 in India: Vulnerable migrant population and an added menace of substance abuse. Ind Psychiatry J 2021; 30:364-365. [PMID: 35017827 PMCID: PMC8709529 DOI: 10.4103/ipj.ipj_168_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 05/18/2021] [Accepted: 05/18/2021] [Indexed: 11/04/2022] Open
Affiliation(s)
- Rishi Sharma
- Department of Forensic Medine and Toxicology, AIIMS, Rishikesh, Uttarakhand, India
| | - Renu Bisht
- Faculty of Life Sciences and Biotechnology, South Asian University (SAU), New Delhi, India
| | | | - Ashish Ramesh Bhute
- Department of Forensic Medine and Toxicology, AIIMS, Rishikesh, Uttarakhand, India
| | - Binaya Kumar Bastia
- Department of Forensic Medine and Toxicology, AIIMS, Rishikesh, Uttarakhand, India
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Bisht R, Bhattacharyya A, Shrivastava A, Saxena P. An Overview of the Medicinally Important Plant Type III PKS Derived Polyketides. Front Plant Sci 2021; 12:746908. [PMID: 34721474 PMCID: PMC8551677 DOI: 10.3389/fpls.2021.746908] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 09/08/2021] [Indexed: 05/06/2023]
Abstract
Plants produce interesting secondary metabolites that are a valuable source of both medicines for human use, along with significant advantages for the manufacturer species. The active compounds which lead to these instrumental effects are generally secondary metabolites produced during various plant growth phases, which provide the host survival advantages while affecting human health inadvertently. Different chemical classes of secondary metabolites are biosynthesized by the plant type III polyketide synthases (PKSs). They are simple homodimeric proteins with the unique mechanistic potential to produce a broad array of secondary metabolites by utilizing simpler starter and extender units. These PKS derived products are majorly the precursors of some important secondary metabolite pathways leading to products such as flavonoids, stilbenes, benzalacetones, chromones, acridones, xanthones, cannabinoids, aliphatic waxes, alkaloids, anthrones, and pyrones. These secondary metabolites have various pharmaceutical, medicinal and industrial applications which make biosynthesizing type III PKSs an important tool for bioengineering purposes. Because of their structural simplicity and ease of manipulation, these enzymes have garnered interest in recent years due to their application in the generation of unnatural natural polyketides and modified products in the search for newer drugs for a variety of health problems. The following review covers the biosynthesis of a variety of type III PKS-derived secondary metabolites, their biological relevance, the associated enzymes, and recent research.
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Saxena P, Joshi Y, Rawat K, Bisht R. Biofilms: Architecture, Resistance, Quorum Sensing and Control Mechanisms. Indian J Microbiol 2019; 59:3-12. [PMID: 30728625 PMCID: PMC6328408 DOI: 10.1007/s12088-018-0757-6] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 08/08/2018] [Indexed: 12/11/2022] Open
Abstract
Biofilm is a mode of living employed by many pathogenic and environmental microbes to proliferate as multicellular aggregates on inert inanimate or biological substrates. Several microbial diseases are associated with biofilms that pose challenges in treatment with antibiotics targeting individual cells. Bacteria in biofilms secrete exopolymeric substances that contribute to architectural stability and provide a secure niche to inhabiting cells. Quorum sensing (QS) plays essential roles in biofilm development. Pathogenic bacteria in biofilms utilize QS mechanisms to activate virulence and develop antibiotic resistance. This review is a brief overview of biofilm research and provides updates on recent understandings on biofilm development, antibiotic resistance and transmission, and importance of QS mechanisms. Strategies to combat biofilm associated diseases including anti-biofilm substances, quorum quenching molecules, bio-surfactants and competitive inhibitors are briefly discussed. The review concludes with updates on recent approaches utilized for biofilm inhibition and provides perspectives for further research in the field.
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Affiliation(s)
- Priti Saxena
- Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, 110021 India
| | - Yogesh Joshi
- Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, 110021 India
| | - Kartik Rawat
- Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, 110021 India
| | - Renu Bisht
- Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, 110021 India
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Parvez A, Giri S, Bisht R, Saxena P. New Insights on Cyclization Specificity of Fungal Type III Polyketide Synthase, PKSIII Nc in Neurospora crassa. Indian J Microbiol 2018; 58:268-277. [PMID: 30013270 PMCID: PMC6023819 DOI: 10.1007/s12088-018-0738-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 05/03/2018] [Indexed: 12/13/2022] Open
Abstract
Type III polyketide synthases (PKSs) biosynthesize varied classes of metabolites with diverse bio-functionalities. Inherent promiscuous substrate specificity, multiple elongations of reaction intermediates and several modes of ring-closure, confer the proteins with the ability to generate unique scaffolds from limited substrate pools. Structural studies have identified crucial amino acid residues that dictate type III PKS functioning, though cyclization specific residues need further investigation. PKSIIINc, a functionally and structurally characterized type III PKS from the fungus, Neurospora crassa, is known to biosynthesize alkyl-resorcinol, alkyl-triketide- and alkyl-tetraketide-α-pyrone products. In this study, we attempted to identify residue positions governing cyclization specificity in PKSIIINc through comparative structural analysis. Structural comparisons with other type III PKSs revealed a motif with conserved hydroxyl/thiol groups that could dictate PKSIIINc catalysis. Site-directed mutagenesis of Cys120 and Ser186 to Ser and Cys, respectively, altered product profiles of mutant proteins. While both C120S and S186C proteins retained wild-type PKSIIINc product activity, S186C favoured lactonization and yielded higher amounts of the α-pyrone products. Notably, C120S gained new cyclization capability and biosynthesized acyl-phloroglucinol in addition to wild-type PKSIIINc products. Generation of alkyl-resorcinol and acyl-phloroglucinol by a single protein is a unique observation in fungal type III PKS family. Mutation of Cys120 to bulky Phe side-chain abrogated formation of tetraketide products and adversely affected overall protein stability as revealed by molecular dynamics simulation studies. Our investigations identify residue positions governing cyclization programming in PKSIIINc protein and provide insights on how subtle variations in protein cores dictate product profiles in type III PKS family.
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Affiliation(s)
- Amreesh Parvez
- Chemical Biology Group, Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, 110021 India
| | - Samir Giri
- Chemical Biology Group, Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, 110021 India
- Present Address: Department of Ecology, School of Biology, University of Osnabrück, Osnabrück, 49076 Germany
| | - Renu Bisht
- Chemical Biology Group, Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, 110021 India
| | - Priti Saxena
- Chemical Biology Group, Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, 110021 India
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Agarwal M, Dubey S, Bisht R. Synthesis and Characterization of nZVI Grafted Alumina and Its Application for Fluoride Removal from Drinking Water: Equilibrium and Kinetics Study. Period Polytech Chem Eng 2018. [DOI: 10.3311/ppch.11838] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
In the present study attempt was made to synthesize iron nanoparticles in the presence of alumina (Al-nZVI) by sodium borohydride reduction process. The composite adsorbent has been characterized using various analytical techniques such as scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and transmission electron microscopy which showed that iron nanoparticles were partially dispersed on alumina surface, with their diameter being in the range 40–100 nm. The batch adsorption experiments were carried out to study the effect of different parameters. The maximum removal of fluoride was obtained at optimal condition of pH 5.0 and dose = 1.8 g/L and was observed to be 94% with contact time of 60 min at 40 °C and initial concentration of 2 mg/L. The adsorption data fitted that pseudo second order kinetics and followed Langmuir isotherm model with maximum adsorption capacity of 10.06 mg/g. Thermodynamic study revealed exothermic nature of adsorption.
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Parvez A, Giri S, Giri GR, Kumari M, Bisht R, Saxena P. Novel Type III Polyketide Synthases Biosynthesize Methylated Polyketides in Mycobacterium marinum. Sci Rep 2018; 8:6529. [PMID: 29695799 PMCID: PMC5916927 DOI: 10.1038/s41598-018-24980-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 04/12/2018] [Indexed: 01/09/2023] Open
Abstract
Mycobacterial pathogenesis is hallmarked by lipidic polyketides that decorate the cell envelope and mediate infection. However, factors mediating persistence remain largely unknown. Dynamic cell wall remodeling could facilitate the different pathogenic phases. Recent studies have implicated type III polyketide synthases (PKSs) in cell wall alterations in several bacteria. Comparative genome analysis revealed several type III pks gene clusters in mycobacteria. In this study, we report the functional characterization of two novel type III PKSs, MMAR_2470 and MMAR_2474, in Mycobacterium marinum. These type III pkss belong to a unique pks genomic cluster conserved exclusively in pathogenic mycobacteria. Cell-free reconstitution assays and high-resolution mass spectrometric analyses revealed methylated polyketide products in independent reactions of both proteins. MMAR_2474 protein exceptionally biosynthesized methylated alkyl-resorcinol and methylated acyl-phloroglucinol products from the same catalytic core. Structure-based homology modeling, product docking, and mutational studies identified residues that could facilitate the distinctive catalysis of these proteins. Functional investigations in heterologous mycobacterial strain implicated MMAR_2474 protein to be vital for mycobacterial survival in stationary biofilms. Our investigations provide new insights into type III PKSs conserved in pathogenic mycobacterial species.
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Affiliation(s)
- Amreesh Parvez
- Chemical Biology Group, Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, 110021, India
| | - Samir Giri
- Chemical Biology Group, Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, 110021, India.,Department of Ecology, School of Biology, University of Osnabrück, Osnabrück, 49076, Germany
| | - Gorkha Raj Giri
- Chemical Biology Group, Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, 110021, India
| | - Monika Kumari
- Chemical Biology Group, Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, 110021, India.,Department of Biochemistry, University College of Medical Sciences, Delhi, 110095, India
| | - Renu Bisht
- Chemical Biology Group, Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, 110021, India
| | - Priti Saxena
- Chemical Biology Group, Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, 110021, India.
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Rupenthal I, Yasin N, Bisht R, Chen Y, Jin J, Jaiswal J, Svirskis D. Stimuli-responsive systems for tuneable ocular drug delivery. Acta Ophthalmol 2016. [DOI: 10.1111/j.1755-3768.2016.0047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Bisht R, Kale S, Natanasabapathi G, Singh M, Agarwal D, Rath G, Julka P, Kumar P, Thulkar S, Garg A, Sharma B. SU-F-T-593: Technical Treatment Accuracy in a Clinic of Fractionated Stereotactic Radiosurgery. Med Phys 2016. [DOI: 10.1118/1.4956778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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10
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Bisht R, Kale S, Gopishankar N, Rath G, Julka P, Agarwal D, Singh M, Garg A, Kumar P, Thulkar S, Sharma B. SU-E-T-563: Multi-Fraction Stereotactic Radiosurgery with Extend System of Gamma Knife: Treatment Verification Using Indigenously Designed Patient Simulating Multipurpose Phantom. Med Phys 2015. [DOI: 10.1118/1.4924925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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11
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Negi JS, Bisht VK, Bhandari AK, Kuniyal CP, Bhatt VP, Bisht R. Chemical fingerprinting and antibacterial activity of Saussurea lappa clarke. APPL BIOCHEM MICRO+ 2014. [DOI: 10.1134/s0003683814060118] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Subramani V, Singh M, Sharma S, Bisht R, Gopishankar N, Rath G. SU-E-T-268: Evaluation of Photoneutron Contamination in Elekta Synergy-S High-Energy Linear Accelerator and Indigenous Novel Solution: The AIIMS Experience. Med Phys 2012; 39:3765. [PMID: 28517258 DOI: 10.1118/1.4735335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The photoneutron contamination problem was encountered due to laminated barrier wall and short maze. The purpose of this study was to report our experience in evaluating the photoneutron contamination during radiation safety survey and solution. METHODS The photoneutron contamination measurement was carried out in Elekta Synergy-S high-energylinear accelerator for 15MV beam. A NE Neutron survey meter and for photon, Victoreen and RADOS survey meters were used. The laminated barrier wall composed of 37cm steel with 30cm concrete both side and short maze length of 5 meter. During safety survey, higher photoneutron levels for 15MV X-rays at treatment room door found. The effect of photoneutron contamination as function of neutron shielding materials of wood, polyethylene and boron and thickness, distance, locations and directions to the control console at distance upto 7 meter were investigated for 4 gantry angles at locations of treatment room entry doors namely door1(A), door2(B), console(C), conduit (D) and above-ceiling(G) for 15MV. RESULTS The initial safety survey showed that neutron level of 47mR/h and photon leakage of 3.2mR/hr at the treatment entry room door1. The neutron values could bring down to the level of acceptance at the treatment entry door2, but the photon values are not acceptable. Therefore, 30cm concrete wall block was made at the location of door2 and another bend was taken. Finally, treatment entrance room door was made using 3cm polyethylene neutron shielding materials in order to achieve the both neutron contamination and photon leakage within the acceptable levels. CONCLUSIONS The neutron sliding-door is operated manually in finger-push by technologist for day-to-day usage. This simple solution is cost effective and increases the patient throughput. This study underlines that one needs to take appropriate safety measures prior to facility design whenever the space constraints situations arises for high energy linear accelerator.
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Affiliation(s)
- V Subramani
- All India Institute of Medical Sciences (AIIMS), New Delhi, Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi.,All India Institute of Medical Sciences, New Delhi.,All India Institute of Medical Sciences, New Delhi, New Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi
| | - M Singh
- All India Institute of Medical Sciences (AIIMS), New Delhi, Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi.,All India Institute of Medical Sciences, New Delhi.,All India Institute of Medical Sciences, New Delhi, New Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi
| | - S Sharma
- All India Institute of Medical Sciences (AIIMS), New Delhi, Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi.,All India Institute of Medical Sciences, New Delhi.,All India Institute of Medical Sciences, New Delhi, New Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi
| | - R Bisht
- All India Institute of Medical Sciences (AIIMS), New Delhi, Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi.,All India Institute of Medical Sciences, New Delhi.,All India Institute of Medical Sciences, New Delhi, New Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi
| | - N Gopishankar
- All India Institute of Medical Sciences (AIIMS), New Delhi, Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi.,All India Institute of Medical Sciences, New Delhi.,All India Institute of Medical Sciences, New Delhi, New Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi
| | - G Rath
- All India Institute of Medical Sciences (AIIMS), New Delhi, Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi.,All India Institute of Medical Sciences, New Delhi.,All India Institute of Medical Sciences, New Delhi, New Delhi.,All India Institute of Medical Sciences, NewDelhi, Delhi
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Gopishankar N, Watanabe Y, Vivekanandhan S, Senthilkumaran S, Kale S, Subramani V, Bisht R, Thulkar S, Rath G, Sharma B. SU-FF-T-537: MRI-Based Polymer Gel Dosimetry for Validating Plans with Multiple Matrices in Gamma Knife Stereotactic Radiosurgery. Med Phys 2009. [DOI: 10.1118/1.3182035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Banerjee K, Guptan RC, Bisht R, Sarin SK, Khandekar P. Identification of a novel surface mutant of hepatitis B virus in a seronegative chronic liver disease patient. Virus Res 1999; 65:103-9. [PMID: 10581383 DOI: 10.1016/s0168-1702(99)00106-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Hepatitis B virus (HBV) with mutations in the envelope proteins can emerge during natural infections, vaccinations or interferon therapy and appears occasionally to escape virus elimination or detection. The implications of such mutations at the molecular level are often obscure. We report the identification of a new surface mutant of HBV. This mutant was identified, and isolated from a chronic liver disease patient, negative for HBsAg as well as other serological markers but positive for HBV DNA. Several mutations were observed in the surface antigen gene out of which a Thr118-Ala118 change was predicted to have a destabilizing effect on the structural integrity of the 'a' determinant and also alter the antigenicity profile of the mutant HBsAg. Besides a RNA hairpin loop was predicted for the transcript generated by the small surface protein of this mutant, which could have an inhibitory effect at the translational level. These observations thus indicate that mutations in the surface gene could lead to a considerable decrease or complete absence of properly folded surface antigen which in turn could explain the absence of reactive HBsAg in the serum of the patient.
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Affiliation(s)
- K Banerjee
- Eukaryotic Gene Expression Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India.
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Gupta SK, Sharma M, Behera AK, Bisht R, Kaul R. Sequence of complementary deoxyribonucleic acid encoding bonnet monkey (Macaca radiata) zona pellucida glycoprotein-ZP1 and its high-level expression in Escherichia coli. Biol Reprod 1997; 57:532-8. [PMID: 9282987 DOI: 10.1095/biolreprod57.3.532] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Zona pellucida (ZP) glycoproteins have been proposed as candidate antigens for immunocontraception. Studies on this potential use can be facilitated by the availability of recombinant proteins. A cDNA lambda gt11 library was constructed using poly(A)+ mRNA isolated from bonnet monkey (Macaca radiata) ovaries and was screened for bonnet monkey ZP1 using a 404-basepair (bp) human ZP1 fragment (nucleotides 818-1221) as probe. Bonnet monkey ZP1 cDNA comprises 1617 nucleotides and encodes a polypeptide of 539 amino acid residues that share 92.0% identity with human ZP1. The major difference between bonnet monkey ZP1 and human ZP1 is the deletion of a 28-amino acid domain (amino acid residues 100-127 corresponding to human ZP1). An internal fragment (1317 bp) of bonnet monkey ZP1, excluding the N-terminus signal sequence and the C-terminus transmembrane-like domain, was amplified by polymerase chain reaction. The amplified Sac I and Kpn I restricted fragment was cloned in a frame downstream of the T5 promoter under the lac operator control for expression in the pQE-30 vector. Recombinant ZP1 (r-ZP1) was expressed as a polyhistidine fusion protein in Escherichia coli strains SG13009[pREP4] and ompT and Ion protease-deficient BL21 (plysS). SDS-PAGE analysis and immunoblotting with a murine monoclonal antibody, MA-410 (raised against porcine ZP3alpha--a homologue of bonnet monkey ZP1--and cross-reactive with bonnet monkey zona pellucida), revealed major bands of 51 and 40 kDa besides truncated fragments. Optimum expression of r-ZP1 was observed at 0.5 mM isopropyl beta-D-thiogalactopyranoside (IPTG). Immunization of male rabbits with r-ZP1 purified on nickel-nitrilotriacetic acid (NTA) resin under denaturing conditions and of female rabbits with r-ZP1 conjugated with diphtheria toxoid-generated antibodies reactive with r-ZP1 in ELISA. Moreover, immune sera, when tested by indirect immunofluorescence on bonnet monkey ovarian sections, showed positive fluorescence with zona pellucida. The information on the sequence of bonnet monkey ZP1 and the availability of the recombinant protein will help toward better understanding and evaluation of the contraceptive potential of homologous immunization in a nonhuman primate model.
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Affiliation(s)
- S K Gupta
- Gamete Antigen Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India.
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Gupta SK, Sengupta J, Bisht R, Bhatnagar A, Kaul R. Human immunodeficiency virus type-1 p24 sequence from an Indian strain: expression in Escherichia coli and implications in diagnostics. Gene X 1997; 190:27-30. [PMID: 9185845 DOI: 10.1016/s0378-1119(96)00697-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A 637-bp fragment, corresponding to the p24 human immunodeficiency virus (HIV) core protein from the gag ORF, was PCR amplified from DNA isolated from peripheral blood mononuclear lymphocytes (PBML) of an asymptomatic HIV-1 seropositive human subject from Bombay and cloned into PCRScript SK(+). The nucleotide sequence revealed highest homology (98.6%) with the consensus sequence of the HIV-1 B subtype. The 637-bp KpnI-HindIII fragment was cloned downstream from a His6 tag in the pQE30 vector under the control of phage T5 promoter leading to production of a 6XHis-p24 fusion protein in Escherichia coli. It showed an approx. 24-kDa band by SDS-PAGE. The recombinant p24 reacted with serum samples from HIV-infected subjects when tested by Western blot and ELISA.
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Affiliation(s)
- S K Gupta
- Gamete Antigen Laboratory, National Institute of Immunology, New Delhi, India.
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Bisht R, Goyal A, Thakur, Singh T, Sharma, Vijay, Goyal BK. Clinico-immunological aspects of vernal catarrh in hilly terrains of Himachal Pradesh. Indian J Ophthalmol 1992; 40:79-82. [PMID: 1302230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Very few immunological studies in vernal catarrh have been conducted in India and abroad, but none in Himachal Pradesh in spite of its high incidence in the State. In the present study 25 patients of vernal catarrh residing at a height ranging between 1000 to 2500 meters above mean sea level have been evaluated. Their immunological status of serum and tears after detailed clinical assessment was studied by single radial immunodiffusion technique of Mancini et al. The values of serum IgA and IgM were significantly higher in patients than in controls. The serum IgE level had no significant difference. The IgG was significantly lower in patients with vernal catarrh. The values of tear IgM, IgE and IgA in these patients were significantly higher than in controls. However, in no case or control group C3C and C4 were detected in tears. The limbal type of vernal catarrh was found to be the most common in this part of the country. No mixed case was seen. Derangement of the immune system in the pathogenesis of vernal catarrh is suggested.
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Affiliation(s)
- R Bisht
- Department of Ophthalmology and Microbiology, Indira Gandhi Medical College, Shimla, Himachal Pradesh
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