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Lensink MF, Brysbaert G, Raouraoua N, Bates PA, Giulini M, Honorato RV, van Noort C, Teixeira JMC, Bonvin AMJJ, Kong R, Shi H, Lu X, Chang S, Liu J, Guo Z, Chen X, Morehead A, Roy RS, Wu T, Giri N, Quadir F, Chen C, Cheng J, Del Carpio CA, Ichiishi E, Rodriguez‐Lumbreras LA, Fernandez‐Recio J, Harmalkar A, Chu L, Canner S, Smanta R, Gray JJ, Li H, Lin P, He J, Tao H, Huang S, Roel‐Touris J, Jimenez‐Garcia B, Christoffer CW, Jain AJ, Kagaya Y, Kannan H, Nakamura T, Terashi G, Verburgt JC, Zhang Y, Zhang Z, Fujuta H, Sekijima M, Kihara D, Khan O, Kotelnikov S, Ghani U, Padhorny D, Beglov D, Vajda S, Kozakov D, Negi SS, Ricciardelli T, Barradas‐Bautista D, Cao Z, Chawla M, Cavallo L, Oliva R, Yin R, Cheung M, Guest JD, Lee J, Pierce BG, Shor B, Cohen T, Halfon M, Schneidman‐Duhovny D, Zhu S, Yin R, Sun Y, Shen Y, Maszota‐Zieleniak M, Bojarski KK, Lubecka EA, Marcisz M, Danielsson A, Dziadek L, Gaardlos M, Gieldon A, Liwo A, Samsonov SA, Slusarz R, Zieba K, Sieradzan AK, Czaplewski C, Kobayashi S, Miyakawa Y, Kiyota Y, Takeda‐Shitaka M, Olechnovic K, Valancauskas L, Dapkunas J, Venclovas C, Wallner B, Yang L, Hou C, He X, Guo S, Jiang S, Ma X, Duan R, Qui L, Xu X, Zou X, Velankar S, Wodak SJ. Impact of AlphaFold on structure prediction of protein complexes: The CASP15-CAPRI experiment. Proteins 2023; 91:1658-1683. [PMID: 37905971 PMCID: PMC10841881 DOI: 10.1002/prot.26609] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/22/2023] [Accepted: 09/28/2023] [Indexed: 11/02/2023]
Abstract
We present the results for CAPRI Round 54, the 5th joint CASP-CAPRI protein assembly prediction challenge. The Round offered 37 targets, including 14 homodimers, 3 homo-trimers, 13 heterodimers including 3 antibody-antigen complexes, and 7 large assemblies. On average ~70 CASP and CAPRI predictor groups, including more than 20 automatics servers, submitted models for each target. A total of 21 941 models submitted by these groups and by 15 CAPRI scorer groups were evaluated using the CAPRI model quality measures and the DockQ score consolidating these measures. The prediction performance was quantified by a weighted score based on the number of models of acceptable quality or higher submitted by each group among their five best models. Results show substantial progress achieved across a significant fraction of the 60+ participating groups. High-quality models were produced for about 40% of the targets compared to 8% two years earlier. This remarkable improvement is due to the wide use of the AlphaFold2 and AlphaFold2-Multimer software and the confidence metrics they provide. Notably, expanded sampling of candidate solutions by manipulating these deep learning inference engines, enriching multiple sequence alignments, or integration of advanced modeling tools, enabled top performing groups to exceed the performance of a standard AlphaFold2-Multimer version used as a yard stick. This notwithstanding, performance remained poor for complexes with antibodies and nanobodies, where evolutionary relationships between the binding partners are lacking, and for complexes featuring conformational flexibility, clearly indicating that the prediction of protein complexes remains a challenging problem.
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Affiliation(s)
- Marc F. Lensink
- Univ. Lille, CNRS, UMR8576 – UGSF – Unité de Glycobiologie Structurale et FonctionnelleLilleFrance
| | - Guillaume Brysbaert
- Univ. Lille, CNRS, UMR8576 – UGSF – Unité de Glycobiologie Structurale et FonctionnelleLilleFrance
| | - Nessim Raouraoua
- Univ. Lille, CNRS, UMR8576 – UGSF – Unité de Glycobiologie Structurale et FonctionnelleLilleFrance
| | - Paul A. Bates
- Biomolecular Modeling LaboratoryThe Francis Crick InstituteLondonUK
| | - Marco Giulini
- Bijvoet Center for Biomolecular Research, Faculty of Science – ChemistryUtrecht UniversityUtrechtThe Netherlands
| | - Rodrigo V. Honorato
- Bijvoet Center for Biomolecular Research, Faculty of Science – ChemistryUtrecht UniversityUtrechtThe Netherlands
| | - Charlotte van Noort
- Bijvoet Center for Biomolecular Research, Faculty of Science – ChemistryUtrecht UniversityUtrechtThe Netherlands
| | - Joao M. C. Teixeira
- Bijvoet Center for Biomolecular Research, Faculty of Science – ChemistryUtrecht UniversityUtrechtThe Netherlands
| | - Alexandre M. J. J. Bonvin
- Bijvoet Center for Biomolecular Research, Faculty of Science – ChemistryUtrecht UniversityUtrechtThe Netherlands
| | - Ren Kong
- Institute of Bioinformatics and Medical Engineering, School of Electrical and Information EngineeringJiangsu University of TechnologyChangzhouChina
| | - Hang Shi
- Institute of Bioinformatics and Medical Engineering, School of Electrical and Information EngineeringJiangsu University of TechnologyChangzhouChina
| | - Xufeng Lu
- Institute of Bioinformatics and Medical Engineering, School of Electrical and Information EngineeringJiangsu University of TechnologyChangzhouChina
| | - Shan Chang
- Institute of Bioinformatics and Medical Engineering, School of Electrical and Information EngineeringJiangsu University of TechnologyChangzhouChina
| | - Jian Liu
- Dept. of Electrical Engineering and Computer ScienceUniversity of MissouriColumbiaMissouriUSA
| | - Zhiye Guo
- Dept. of Electrical Engineering and Computer ScienceUniversity of MissouriColumbiaMissouriUSA
| | - Xiao Chen
- Dept. of Electrical Engineering and Computer ScienceUniversity of MissouriColumbiaMissouriUSA
| | - Alex Morehead
- Dept. of Electrical Engineering and Computer ScienceUniversity of MissouriColumbiaMissouriUSA
| | - Raj S. Roy
- Dept. of Electrical Engineering and Computer ScienceUniversity of MissouriColumbiaMissouriUSA
| | - Tianqi Wu
- Dept. of Electrical Engineering and Computer ScienceUniversity of MissouriColumbiaMissouriUSA
| | - Nabin Giri
- Dept. of Electrical Engineering and Computer ScienceUniversity of MissouriColumbiaMissouriUSA
| | - Farhan Quadir
- Dept. of Electrical Engineering and Computer ScienceUniversity of MissouriColumbiaMissouriUSA
| | - Chen Chen
- Dept. of Electrical Engineering and Computer ScienceUniversity of MissouriColumbiaMissouriUSA
| | - Jianlin Cheng
- Dept. of Electrical Engineering and Computer ScienceUniversity of MissouriColumbiaMissouriUSA
| | | | - Eichiro Ichiishi
- International University of Health and Welfare (IUHV Hospital)Nasushiobara‐CityJapan
| | - Luis A. Rodriguez‐Lumbreras
- Instituto de Ciencias de la Vida y del Vino (ICVV)CSIC ‐ Universidad de La Rioja ‐ Gobierno de La RiojaLogronoSpain
- Barcelona Supercomputing Center (BSC)BarcelonaSpain
| | - Juan Fernandez‐Recio
- Instituto de Ciencias de la Vida y del Vino (ICVV)CSIC ‐ Universidad de La Rioja ‐ Gobierno de La RiojaLogronoSpain
- Barcelona Supercomputing Center (BSC)BarcelonaSpain
| | - Ameya Harmalkar
- Dept. of Chemical and Biomolecular EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Lee‐Shin Chu
- Dept. of Chemical and Biomolecular EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Sam Canner
- Dept. of Chemical and Biomolecular EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Rituparna Smanta
- Dept. of Chemical and Biomolecular EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Jeffrey J. Gray
- Dept. of Chemical and Biomolecular EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA
- Program in Molecular BiophysicsJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Hao Li
- School of PhysicsHuazhong University of Science and TechnologyWuhanChina
| | - Peicong Lin
- School of PhysicsHuazhong University of Science and TechnologyWuhanChina
| | - Jiahua He
- School of PhysicsHuazhong University of Science and TechnologyWuhanChina
| | - Huanyu Tao
- School of PhysicsHuazhong University of Science and TechnologyWuhanChina
| | - Sheng‐You Huang
- School of PhysicsHuazhong University of Science and TechnologyWuhanChina
| | - Jorge Roel‐Touris
- Protein Design and Modeling Lab, Dept. of Structural BiologyMolecular Biology Institute of Barcelona (IBMB‐CSIC)BarcelonaSpain
| | | | | | - Anika J. Jain
- Dept. of Biological SciencesPurdue UniversityWest LafayetteIndianaUSA
| | - Yuki Kagaya
- Dept. of Biological SciencesPurdue UniversityWest LafayetteIndianaUSA
| | - Harini Kannan
- Dept. of Biological SciencesPurdue UniversityWest LafayetteIndianaUSA
- Dept. of Biotechnology, Bhupat and Jyoti Mehta School of BiosciencesIndian Institute of Technology MadrasChennaiIndia
| | - Tsukasa Nakamura
- Dept. of Biological SciencesPurdue UniversityWest LafayetteIndianaUSA
| | - Genki Terashi
- Dept. of Biological SciencesPurdue UniversityWest LafayetteIndianaUSA
| | - Jacob C. Verburgt
- Dept. of Biological SciencesPurdue UniversityWest LafayetteIndianaUSA
| | - Yuanyuan Zhang
- Dept. of Computer SciencePurdue UniversityWest LafayetteIndianaUSA
| | - Zicong Zhang
- Dept. of Computer SciencePurdue UniversityWest LafayetteIndianaUSA
| | - Hayato Fujuta
- Dept. of Biotechnology, Bhupat and Jyoti Mehta School of BiosciencesIndian Institute of Technology MadrasChennaiIndia
| | | | - Daisuke Kihara
- Dept. of Computer SciencePurdue UniversityWest LafayetteIndianaUSA
- Dept. of Biological SciencesPurdue UniversityWest LafayetteIndianaUSA
| | | | | | | | | | | | | | | | - Surendra S. Negi
- Sealy Center for Structural Biology and Molecular BiophysicsUniversity of Texas Medical BranchGalvestonTexasUSA
| | | | | | - Zhen Cao
- King Abdullah University of Science and Technology (KAUST)Saudi Arabia
| | - Mohit Chawla
- King Abdullah University of Science and Technology (KAUST)Saudi Arabia
| | - Luigi Cavallo
- King Abdullah University of Science and Technology (KAUST)Saudi Arabia
- Department of Chemistry and BiologyUniversity of SalernoFiscianoItaly
| | | | - Rui Yin
- University of Maryland Institute for Bioscience and Biotechnology ResearchRockvilleMarylandUSA
- Dept. of Cell Biology and Molecular GeneticsUniversity of MarylandCollege ParkMarylandUSA
| | - Melyssa Cheung
- University of Maryland Institute for Bioscience and Biotechnology ResearchRockvilleMarylandUSA
- Dept. of Chemistry and BiochemistryUniversity of MarylandCollege ParkMarylandUSA
| | - Johnathan D. Guest
- University of Maryland Institute for Bioscience and Biotechnology ResearchRockvilleMarylandUSA
- Dept. of Cell Biology and Molecular GeneticsUniversity of MarylandCollege ParkMarylandUSA
| | - Jessica Lee
- University of Maryland Institute for Bioscience and Biotechnology ResearchRockvilleMarylandUSA
- Dept. of Cell Biology and Molecular GeneticsUniversity of MarylandCollege ParkMarylandUSA
| | - Brian G. Pierce
- University of Maryland Institute for Bioscience and Biotechnology ResearchRockvilleMarylandUSA
- Dept. of Cell Biology and Molecular GeneticsUniversity of MarylandCollege ParkMarylandUSA
| | - Ben Shor
- School of Computer Science and EngineeringThe Hebrew University of JerusalemJerusalemIsrael
| | - Tomer Cohen
- School of Computer Science and EngineeringThe Hebrew University of JerusalemJerusalemIsrael
| | - Matan Halfon
- School of Computer Science and EngineeringThe Hebrew University of JerusalemJerusalemIsrael
| | | | - Shaowen Zhu
- Department of Electrical and Computer EngineeringTexas A&M UniversityCollege StationTexasUSA
| | - Rujie Yin
- Department of Electrical and Computer EngineeringTexas A&M UniversityCollege StationTexasUSA
| | - Yuanfei Sun
- Department of Electrical and Computer EngineeringTexas A&M UniversityCollege StationTexasUSA
| | - Yang Shen
- Department of Electrical and Computer EngineeringTexas A&M UniversityCollege StationTexasUSA
- Department of Computer Science and EngineeringTexas A&M UniversityCollege StationTexasUSA
- Institute of Biosciences and Technology and Department of Translational Medical SciencesTexas A&M UniversityHoustonTexasUSA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Yuta Miyakawa
- School of PharmacyKitasato UniversityMinato‐kuTokyoJapan
| | - Yasuomi Kiyota
- School of PharmacyKitasato UniversityMinato‐kuTokyoJapan
| | | | - Kliment Olechnovic
- Institute of Biotechnology, Life Sciences CenterVilnius UniversityVilniusLithuania
| | - Lukas Valancauskas
- Institute of Biotechnology, Life Sciences CenterVilnius UniversityVilniusLithuania
| | - Justas Dapkunas
- Institute of Biotechnology, Life Sciences CenterVilnius UniversityVilniusLithuania
| | - Ceslovas Venclovas
- Institute of Biotechnology, Life Sciences CenterVilnius UniversityVilniusLithuania
| | - Bjorn Wallner
- Bioinformatics Division, Department of Physics, Chemistry, and BiologyLinkoping UniversityLinköpingSweden
| | - Lin Yang
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Center for Composite Materials and StructuresHarbin Institute of TechnologyHarbinChina
- School of Aerospace, Mechanical and Mechatronic EngineeringThe University of SydneyNew South WalesAustralia
| | - Chengyu Hou
- School of Electronics and Information EngineeringHarbin Institute of TechnologyHarbinChina
| | - Xiaodong He
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Center for Composite Materials and StructuresHarbin Institute of TechnologyHarbinChina
- Shenzhen STRONG Advanced Materials Research Institute Col, LtdShenzhenPeople's Republic of China
| | - Shuai Guo
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Center for Composite Materials and StructuresHarbin Institute of TechnologyHarbinChina
| | - Shenda Jiang
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Center for Composite Materials and StructuresHarbin Institute of TechnologyHarbinChina
| | - Xiaoliang Ma
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Center for Composite Materials and StructuresHarbin Institute of TechnologyHarbinChina
| | - Rui Duan
- Dalton Cardiovascular Research CenterUniversity of MissouriColumbiaMissouriUSA
| | - Liming Qui
- Dalton Cardiovascular Research CenterUniversity of MissouriColumbiaMissouriUSA
| | - Xianjin Xu
- Dalton Cardiovascular Research CenterUniversity of MissouriColumbiaMissouriUSA
| | - Xiaoqin Zou
- Dalton Cardiovascular Research CenterUniversity of MissouriColumbiaMissouriUSA
- Dept. of Physics and AstronomyUniversity of MissouriColumbiaMissouriUSA
- Dept. of BiochemistryUniversity of MissouriColumbiaMissouriUSA
- Institute for Data Science and InformaticsUniversity of MissouriColumbiaMissouriUSA
| | - Sameer Velankar
- Protein Data Bank in Europe, European Molecular Biology LaboratoryEuropean Bioinformatics Institute (EMBL‐EBI)HinxtonCambridgeUK
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Canon N, Schein CH, Braun W, Negi SS, Chen X, Kulis MD, Kim EH, Pathy V, Pozzoli M, Liu W, Dreskin SC. Alanine Scanning of the Unstructured Region of Ara h 2 and of a Related Mimotope Reveals Critical Amino Acids for IgE Binding. Mol Nutr Food Res 2023; 67:e2300134. [PMID: 37706599 PMCID: PMC10840829 DOI: 10.1002/mnfr.202300134] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 07/26/2023] [Indexed: 09/15/2023]
Abstract
SCOPE The unstructured region of Ara h 2, referred to as epitope 3, contains a repeated motif, DYPSh (h = hydroxyproline) that is important for IgE binding. METHODS AND RESULTS IgE binding assays to 20mer and shorter peptides of epitope 3, defines a 16mer core sequence containing one copy of the DPYSh motif, DEDSYERDPYShSQDP. This study performs alanine scanning of this and a related 12mer mimotope, LLDPYAhRAWTK. IgE binding, using a pool of 10 sera and with individual sera, is greatly reduced when alanine is substituted for aspartate at position 8 (D8; p < 0.01), tyrosine at position 10 (Y10; p < 0.01), and hydroxyproline at position 12 (h12; p < 0.001). IgE binding to alanine-substituted peptides of a mimotope containing the DPY_h motif confirm the critical importance of Y (p < 0.01) and h (p < 0.01), but not D. Molecular modeling of the core and mimotope suggests an h-dependent conformational basis for the recognition of these sequences by polyclonal IgE. CONCLUSIONS IgE from pooled sera and individual sera differentially bound amino acids throughout the sequences of Epitope 3 and its mimotope, with Y10 and h12 being most important for all sera. These results are highly significant for designing hypoallergenic forms of Ara h 2.
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Affiliation(s)
- Nicole Canon
- Division of Allergy and Immunology, Kelsey-Seybold Clinic, Houston, TX
| | - Catherine H. Schein
- Institute for Human Infections and Immunity (IHII), The University of Texas Medical Branch, Galveston, TX
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX
| | - Werner Braun
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX
| | - Surendra S. Negi
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX
| | - Xueni Chen
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Michael D. Kulis
- Division of Pediatric Allergy and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC
| | - Edwin H. Kim
- Division of Pediatric Allergy and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC
| | - Vidya Pathy
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Marina Pozzoli
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Weimin Liu
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Stephen C. Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
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Negi SS, Schein CH, Braun W. The updated Structural Database of Allergenic Proteins (SDAP 2.0) provides 3D models for allergens and incorporated bioinformatics tools. J Allergy Clin Immunol Glob 2023; 2:100162. [PMID: 37781674 PMCID: PMC10509899 DOI: 10.1016/j.jacig.2023.100162] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 07/07/2023] [Accepted: 07/08/2023] [Indexed: 10/03/2023]
Abstract
Background Allergenic proteins can cause IgE-mediated adverse reactions in sensitized individuals. Although the sequences of many allergenic proteins have been identified, bioinformatics data analysis with advanced computational methods and modeling is needed to identify the basis for IgE binding and cross-reactivity. Objective We aim to present the features and use of the updated Structural Database of Allergenic Proteins 2.0 (SDAP 2.0) webserver, a unique, publicly available resource to compare allergens using specially designed computational tools and new high-quality 3-D models for most known allergens. Methods Previously developed and novel software tools for identifying cross-reactive allergens using sequence and structure similarity are implemented in SDAP 2.0. A comprehensive set of high-quality 3-D models of most allergens was generated with the state-of-the-art AlphaFold 2 software. A graphics tool enables the interactive visualization of IgE epitopes on experimentally determined and modeled 3-D structures. Results A user can search for allergens similar to a given input sequence with the FASTA algorithm or the window-based World Health Organization/International Union of Immunological Societies (WHO/IUIS) guidelines on safety concerns of novel food products. Peptides similar to known IgE epitopes can be identified with the property distance tool and conformational epitopes by the Cross-React method. The updated database contains 1657 manually curated sequences including all allergens from the IUIS database, 334 experimentally determined X-ray or NMR structures, and 1565 3-D models. Each allergen/isoallergen is classified according to its protein family. Conclusions SDAP provides access to the steadily increasing information on allergenic structures and epitopes with integrated bioinformatics tools to identify and analyze their similarities. In addition to serving the research and regulatory community, it provides clinicians with tools to identify potential coallergies in a sensitive patient and can help companies to design hypoallergenic foods and immunotherapies.
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Affiliation(s)
- Surendra S. Negi
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, Tex
- Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, Tex
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex
| | - Catherine H. Schein
- Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, Tex
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex
| | - Werner Braun
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, Tex
- Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, Tex
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex
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Schein CH, Negi SS, Braun W. Still SDAPing Along: 20 Years of the Structural Database of Allergenic Proteins. Front Allergy 2022; 3:863172. [PMID: 35386653 PMCID: PMC8974667 DOI: 10.3389/falgy.2022.863172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 02/28/2022] [Indexed: 11/13/2022] Open
Abstract
The introduction of plant extracts to mitigate the symptoms of “hay fever”, about a century ago, led to discoveries beginning sixty years ago on determining the sequences and eventually structures of allergenic proteins. As more proteins were cloned, there was a need to rapidly identify and categorize those with significant similarity to known allergens. The Structural Database of Allergenic Proteins (SDAP) was created at the beginning of the 21st century as the first cross-referenced website to allow rapid overview of the structures and sequences of allergenic proteins. SDAP provides a way to identify sequence and functional similarities between these proteins, despite the complex nomenclature system based on the Latin names of their different sources. A rapid FASTA search simplifies grouping allergens from the same structural or functional family. SDAP also provides an overview of the rapidly expanding literature on the sequence, structure and epitopes of allergenic proteins and a way to estimate the potential allergenicity of novel proteins based on rules provided by the IUIS. Twenty years and a pandemic later, the list of allergenic proteins and their attributes continues to grow. SDAP is expanding and improving to allow rapid access to all this information.
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Affiliation(s)
- Catherine H. Schein
- Department of Biochemistry and Molecular Biology, Institute for Human Infections and Immunity, University of Texas Medical Branch at Galveston, Galveston, TX, United States
- *Correspondence: Catherine H. Schein
| | - Surendra S. Negi
- Department of Biochemistry and Molecular Biology, Institute for Human Infections and Immunity, University of Texas Medical Branch at Galveston, Galveston, TX, United States
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch at Galveston, Galveston, TX, United States
| | - Werner Braun
- Department of Biochemistry and Molecular Biology, Institute for Human Infections and Immunity, University of Texas Medical Branch at Galveston, Galveston, TX, United States
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch at Galveston, Galveston, TX, United States
- Margaret Maccallum Gage and Tracy Davis Gage Professorship in Biochemistry and Allergies, University of Texas Medical Branch at Galveston, Galveston, TX, United States
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Negi SS, Schein CH, Braun W. Regional and temporal coordinated mutation patterns in SARS-CoV-2 spike protein revealed by a clustering and network analysis. Sci Rep 2022; 12:1128. [PMID: 35064154 PMCID: PMC8782831 DOI: 10.1038/s41598-022-04950-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 12/24/2021] [Indexed: 12/23/2022] Open
Abstract
SARS-CoV-2 has steadily mutated during its spread to > 300 million people throughout the world. The WHO has designated strains with certain mutations, "variants of concern" (VOC), as they may have higher infectivity and/or resist neutralization by antibodies in sera of vaccinated individuals and convalescent patients. Methods to detect regionally emerging VOC are needed to guide treatment and vaccine design. Cluster and network analysis was applied to over 1.2 million sequences of the SARS-CoV-2 spike protein from 36 countries in the GISAID database. While some mutations rapidly spread throughout the world, regionally specific groups of variants were identified. Strains circulating in each country contained different sets of high frequency mutations, many of which were known VOCs. Mutations within clusters increased in frequency simultaneously. Low frequency, but highly correlated mutations detected by the method could signal emerging VOCs, especially if they occur at higher frequency in other regions. An automated version of our method to find high frequency mutations in a set of SARS-COV-2 spike sequences is available online at http://curie.utmb.edu/SAR.html .
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Affiliation(s)
- Surendra S Negi
- Sealy Center for Structural Biology and Biophysics, Department of Biochemistry and Molecular Biology, The University of Texas, Medical Branch, 301 University Blvd, Galveston, TX, 77555-0304, USA
- Institute for Human Infections and Immunity (IHII), The University of Texas Medical Branch, Galveston, TX, 77550, USA
| | - Catherine H Schein
- Sealy Center for Structural Biology and Biophysics, Department of Biochemistry and Molecular Biology, The University of Texas, Medical Branch, 301 University Blvd, Galveston, TX, 77555-0304, USA
- Institute for Human Infections and Immunity (IHII), The University of Texas Medical Branch, Galveston, TX, 77550, USA
| | - Werner Braun
- Sealy Center for Structural Biology and Biophysics, Department of Biochemistry and Molecular Biology, The University of Texas, Medical Branch, 301 University Blvd, Galveston, TX, 77555-0304, USA.
- Institute for Human Infections and Immunity (IHII), The University of Texas Medical Branch, Galveston, TX, 77550, USA.
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Negi SS, Goldblum RM, Braun W, Midoro-Horiuti T. Design of peptides with high affinity binding to a monoclonal antibody as a basis for immunotherapy. Peptides 2021; 145:170628. [PMID: 34411692 PMCID: PMC8484066 DOI: 10.1016/j.peptides.2021.170628] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 11/23/2022]
Abstract
About half of the US population is sensitized to one or more allergens, as found by a National Health and Nutrition Examination Survey (NHANES). The most common treatment for seasonal allergic responses is the daily use of oral antihistamines, which can control some of the symptoms, but are not effective for nasal congestion, and can be debilitating in many patients. Peptide immunotherapy is a promising new approach to treat allergic airway diseases. The small size of the immunogens cannot lead to an unwanted allergic reaction in sensitized patients, and the production of peptides with sufficient amounts for immunotherapy is time- and cost-effective. However, it is not known what peptides are the most effective for an immunotherapy of allergens. We previously produced a unique monoclonal antibody (mAb) E58, which can inhibit the binding of multiple groups of mAbs and human IgEs from patients affected by the major group 1 allergens of ragweed (Amb a 1) and conifer pollens (Jun a 1, Cup s 1, and Cry j 1). Here, we demonstrated that a combined approach, starting from two linear E58 epitopes of the tree pollen allergen Jun a 1 and the ragweed pollen allergen Amb a 1, and residue modifications suggested by molecular docking calculations and peptide design could identify a large number of high affinity binding peptides. We propose that this combined experimental and computational approach by structural analysis of linear IgE epitopes and peptide design, can lead to potential new candidates for peptide immunotherapy.
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Affiliation(s)
- Surendra S Negi
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555-0304, United States
| | - Randall M Goldblum
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555-0304, United States; Department of Pediatrics, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555-0372, United States
| | - Werner Braun
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555-0304, United States.
| | - Terumi Midoro-Horiuti
- Department of Pediatrics, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555-0372, United States.
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Schein CH, Levine CB, McLellan SLF, Negi SS, Braun W, Dreskin SC, Anaya ES, Schmidt J. Synthetic proteins for COVID-19 diagnostics. Peptides 2021; 143:170583. [PMID: 34087220 PMCID: PMC8168367 DOI: 10.1016/j.peptides.2021.170583] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/19/2021] [Accepted: 05/20/2021] [Indexed: 12/24/2022]
Abstract
There is an urgent need for inexpensive, rapid and specific antigen-based assays to test for vaccine efficacy and detect infection with SARS-CoV-2 and its variants. We have identified a small, synthetic protein (JS7), representing a region of maximum variability within the receptor binding domain (RBD), which binds antibodies in sera from nine patients with PCR-verified COVID-19 of varying severity. Antibodies binding to either JS7 or the SARS-CoV-2 recombinant RBD, as well as those that disrupt binding between a fragment of the ACE2 receptor and the RBD, are proportional to disease severity and clinical outcome. Binding to JS7 was inhibited by linear peptides from the RBD interface with ACE2. Variants of JS7, such as E484K or N501Y, can be quickly synthesized in pure form in large quantities by automated methods. JS7 and related synthetic antigens can provide a basis for specific diagnostics for SARS-CoV-2 infections.
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Affiliation(s)
- Catherine H Schein
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, United States; Institute for Human Infections and immunity (IHII), The University of Texas Medical Branch, Galveston, TX, United States.
| | - Corri B Levine
- Institute for Translational Sciences, The University of Texas Medical Branch, Galveston, TX, United States
| | - Susan L F McLellan
- Department of Internal medicine - Infectious Diseases, The University of Texas Medical Branch, Galveston, TX, United States
| | - Surendra S Negi
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, United States; Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX, United States
| | - Werner Braun
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, United States; Institute for Human Infections and immunity (IHII), The University of Texas Medical Branch, Galveston, TX, United States; Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX, United States
| | - Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO, 80045, United States
| | - Elizabeth S Anaya
- B-11 Bioenergy and Biome Sciences, Bioscience Division Los Alamos National Laboratory, Los Alamos, NM, 87545, United States
| | - Jurgen Schmidt
- B-11 Bioenergy and Biome Sciences, Bioscience Division Los Alamos National Laboratory, Los Alamos, NM, 87545, United States
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Dreskin SC, Koppelman SJ, Andorf S, Nadeau KC, Kalra A, Braun W, Negi SS, Chen X, Schein CH. The importance of the 2S albumins for allergenicity and cross-reactivity of peanuts, tree nuts, and sesame seeds. J Allergy Clin Immunol 2021; 147:1154-1163. [PMID: 33217410 PMCID: PMC8035160 DOI: 10.1016/j.jaci.2020.11.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 11/06/2020] [Accepted: 11/10/2020] [Indexed: 12/17/2022]
Abstract
Allergies to peanuts, tree nuts, and sesame seeds are among the most important food-related causes of anaphylaxis. Important clinical questions include: Why is there a variable occurrence of coallergy among these foods and Is this immunologically mediated? The clinical and immunologic data summarized here suggest an immunologic basis for these coallergies that is based on similarities among the 2S albumins. Data from component resolved diagnostics have highlighted the relationship between IgE binding to these allergens and the presence of IgE-mediated food allergy. Furthermore, in vitro and in vivo experiments provide strong evidence that the 2S albumins are the most important allergens in peanuts for inducing an allergic effector response. Although the 2S albumins are diverse, they have a common disulfide-linked core with similar physicochemical properties that make them prime candidates to explain much of the observed coallergy among peanuts, tree nuts, and sesame seeds. The well-established frequency of cashew and pistachio nut coallergy (64%-100%) highlights how the structural similarities among their 2S albumins may account for observed clinical cross-reactivity. A complete understanding of the physicochemical properties of the 2S albumins in peanuts, tree nuts, and sesame seeds will enhance our ability to diagnose, treat, and ultimately prevent these allergies.
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Affiliation(s)
- Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, Colo.
| | - Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science and Technology, University of Nebraska, Lincoln, Neb
| | - Sandra Andorf
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Division of Allergy and Immunology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio; Sean N. Parker Center for Allergy and Asthma Research, Stanford University School of Medicine, Stanford, Calif
| | - Kari C Nadeau
- Sean N. Parker Center for Allergy and Asthma Research, Stanford University School of Medicine, Stanford, Calif
| | - Anjeli Kalra
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, Colo
| | - Werner Braun
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, Tex; Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex
| | - Surendra S Negi
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, Tex; Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex
| | - Xueni Chen
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, Colo
| | - Catherine H Schein
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex; Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Tex.
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9
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Dreskin SC, Germinaro M, Reinhold D, Chen X, Vickery BP, Kulis M, Burks AW, Negi SS, Braun W, Chambliss JM, Eglite S, McNulty CMG. IgE binding to linear epitopes of Ara h 2 in peanut allergic preschool children undergoing oral Immunotherapy. Pediatr Allergy Immunol 2019; 30:817-823. [PMID: 31437325 PMCID: PMC6906227 DOI: 10.1111/pai.13117] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 07/10/2019] [Accepted: 07/31/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND For patients with peanut allergy, there are currently no methods to predict who will develop sustained unresponsiveness (SU) after oral immunotherapy (OIT). OBJECTIVE Assess IgE binding to peanut (PN), Ara h 2, and specific linear epitopes of Ara h 2 as predictors of the important clinical parameters: eliciting dose threshold and attainment of SU following OIT. METHODS Samples and clinical data were collected from children undergoing OIT. PN- and Ara h 2-sIgE were quantified by ImmunoCAP® . IgE binding to linear peptides of Ara h 2 and Ara h 6 was measured with peptide microarrays. RESULTS Values of PN-sIgE correlated with eliciting dose (P = .001) and with a higher likelihood of achieving SU (P < .0001), but these relationships were lost at higher values for PN-sIgE (≥14 kIU for eliciting dose and ≥35 kIU/L for SU). In subjects with PN-sIgE ≥ 14 kIU/L, binding of IgE to epitopes 5 and 6 of Ara h 2 was associated with a lower eliciting dose at baseline challenge (P < .001; Pc < .02). In subjects with PN-sIgE ≥ 35 kIU/L, a combined model of IgE binding to epitopes 1, 5 and 6 with PN-sIgE was highly predictive of attainment of SU (AUC of 0.86; P = .0067). CONCLUSION In young patients with peanut allergy, measurement of PN-sIgE and IgE binding to specific linear epitopes of Ara h 2 in baseline samples may allow stratification of patients regarding sensitivity to challenge and outcome of OIT.
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Affiliation(s)
- Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO, USA
| | | | | | - Xueni Chen
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO, USA
| | - Brian P Vickery
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Michael Kulis
- Division of Allergy and Immunology, Department of Pediatrics, University of North Carolina-Chapel Hill, NC, USA
| | - A Wesley Burks
- Division of Allergy and Immunology, Department of Pediatrics, University of North Carolina-Chapel Hill, NC, USA
| | - Surendra S Negi
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Werner Braun
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Jeffery M Chambliss
- Division of Allergy and Immunology, Department of Pediatrics, University of Texas, Dallas, TX, USA
| | - Spodra Eglite
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO, USA
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10
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Negi SS, Braun W. Cross-React: a new structural bioinformatics method for predicting allergen cross-reactivity. Bioinformatics 2017; 33:1014-1020. [PMID: 28062447 DOI: 10.1093/bioinformatics/btw767] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 12/01/2016] [Indexed: 11/14/2022] Open
Abstract
The phenomenon of cross-reactivity between allergenic proteins plays an important role to understand how the immune system recognizes different antigen proteins. Allergen proteins are known to cross-react if their sequence comparison shows a high sequence identity which also implies that the proteins have a similar 3D fold. In such cases, linear sequence alignment methods are frequently used to predict cross-reactivity between allergenic proteins. However, the prediction of cross-reactivity between distantly related allergens continues to be a challenging task. To overcome this problem, we developed a new structure-based computational method, Cross-React, to predict cross-reactivity between allergenic proteins available in the Structural Database of Allergens (SDAP). Our method is based on the hypothesis that we can find surface patches on 3D structures of potential allergens with amino acid compositions similar to an epitope in a known allergen. We applied the Cross-React method to a diverse set of seven allergens, and successfully identified several cross-reactive allergens with high to moderate sequence identity which have also been experimentally shown to cross-react. Based on these findings, we suggest that Cross-React can be used as a predictive tool to assess protein allergenicity and cross-reactivity. Availability and Implementation : Cross-React is available at: http://curie.utmb.edu/Cross-React.html. Contact ssnegi@utmb.edu.
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11
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Lensink MF, Velankar S, Kryshtafovych A, Huang SY, Schneidman-Duhovny D, Sali A, Segura J, Fernandez-Fuentes N, Viswanath S, Elber R, Grudinin S, Popov P, Neveu E, Lee H, Baek M, Park S, Heo L, Rie Lee G, Seok C, Qin S, Zhou HX, Ritchie DW, Maigret B, Devignes MD, Ghoorah A, Torchala M, Chaleil RAG, Bates PA, Ben-Zeev E, Eisenstein M, Negi SS, Weng Z, Vreven T, Pierce BG, Borrman TM, Yu J, Ochsenbein F, Guerois R, Vangone A, Rodrigues JPGLM, van Zundert G, Nellen M, Xue L, Karaca E, Melquiond ASJ, Visscher K, Kastritis PL, Bonvin AMJJ, Xu X, Qiu L, Yan C, Li J, Ma Z, Cheng J, Zou X, Shen Y, Peterson LX, Kim HR, Roy A, Han X, Esquivel-Rodriguez J, Kihara D, Yu X, Bruce NJ, Fuller JC, Wade RC, Anishchenko I, Kundrotas PJ, Vakser IA, Imai K, Yamada K, Oda T, Nakamura T, Tomii K, Pallara C, Romero-Durana M, Jiménez-García B, Moal IH, Férnandez-Recio J, Joung JY, Kim JY, Joo K, Lee J, Kozakov D, Vajda S, Mottarella S, Hall DR, Beglov D, Mamonov A, Xia B, Bohnuud T, Del Carpio CA, Ichiishi E, Marze N, Kuroda D, Roy Burman SS, Gray JJ, Chermak E, Cavallo L, Oliva R, Tovchigrechko A, Wodak SJ. Prediction of homoprotein and heteroprotein complexes by protein docking and template-based modeling: A CASP-CAPRI experiment. Proteins 2016; 84 Suppl 1:323-48. [PMID: 27122118 PMCID: PMC5030136 DOI: 10.1002/prot.25007] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 12/30/2015] [Accepted: 02/02/2016] [Indexed: 12/26/2022]
Abstract
We present the results for CAPRI Round 30, the first joint CASP-CAPRI experiment, which brought together experts from the protein structure prediction and protein-protein docking communities. The Round comprised 25 targets from amongst those submitted for the CASP11 prediction experiment of 2014. The targets included mostly homodimers, a few homotetramers, and two heterodimers, and comprised protein chains that could readily be modeled using templates from the Protein Data Bank. On average 24 CAPRI groups and 7 CASP groups submitted docking predictions for each target, and 12 CAPRI groups per target participated in the CAPRI scoring experiment. In total more than 9500 models were assessed against the 3D structures of the corresponding target complexes. Results show that the prediction of homodimer assemblies by homology modeling techniques and docking calculations is quite successful for targets featuring large enough subunit interfaces to represent stable associations. Targets with ambiguous or inaccurate oligomeric state assignments, often featuring crystal contact-sized interfaces, represented a confounding factor. For those, a much poorer prediction performance was achieved, while nonetheless often providing helpful clues on the correct oligomeric state of the protein. The prediction performance was very poor for genuine tetrameric targets, where the inaccuracy of the homology-built subunit models and the smaller pair-wise interfaces severely limited the ability to derive the correct assembly mode. Our analysis also shows that docking procedures tend to perform better than standard homology modeling techniques and that highly accurate models of the protein components are not always required to identify their association modes with acceptable accuracy. Proteins 2016; 84(Suppl 1):323-348. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Marc F Lensink
- University Lille, CNRS UMR8576 UGSF, Lille, F-59000, France.
| | - Sameer Velankar
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
| | | | - Shen-You Huang
- Research Support Computing, University of Missouri Bioinformatics Consortium, and Department of Computer Science, University of Missouri, Columbia, Missouri, 65211
| | - Dina Schneidman-Duhovny
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, 94158
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, 94158
| | - Andrej Sali
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, 94158
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, 94158
- California Institute for Quantitative Biosciences (QB3), University of California San Francisco, San Francisco, California, 94158
| | - Joan Segura
- GN7 of the National Institute for Bioinformatics (INB) and Biocomputing Unit, National Center of Biotechnology (CSIC), Madrid, 28049, Spain
| | - Narcis Fernandez-Fuentes
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, SY233FG, United Kingdom
| | - Shruthi Viswanath
- Department of Computer Science, University of Texas at Austin, Austin, Texas, 78712
- Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin, Texas, 78712
| | - Ron Elber
- Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin, Texas, 78712
- Department of Chemistry, University of Texas at Austin, Austin, Texas, 78712
| | - Sergei Grudinin
- LJK, University Grenoble Alpes, CNRS, Grenoble, 38000, France
- INRIA, Grenoble, 38000, France
| | - Petr Popov
- LJK, University Grenoble Alpes, CNRS, Grenoble, 38000, France
- INRIA, Grenoble, 38000, France
- Moscow Institute of Physics and Technology, Dolgoprudniy, Russia
| | - Emilie Neveu
- LJK, University Grenoble Alpes, CNRS, Grenoble, 38000, France
- INRIA, Grenoble, 38000, France
| | - Hasup Lee
- Department of Chemistry, Seoul National University, Seoul, 151-747, Republic of Korea
| | - Minkyung Baek
- Department of Chemistry, Seoul National University, Seoul, 151-747, Republic of Korea
| | - Sangwoo Park
- Department of Chemistry, Seoul National University, Seoul, 151-747, Republic of Korea
| | - Lim Heo
- Department of Chemistry, Seoul National University, Seoul, 151-747, Republic of Korea
| | - Gyu Rie Lee
- Department of Chemistry, Seoul National University, Seoul, 151-747, Republic of Korea
| | - Chaok Seok
- Department of Chemistry, Seoul National University, Seoul, 151-747, Republic of Korea
| | - Sanbo Qin
- Department of Physics and Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida, 32306, USA
| | - Huan-Xiang Zhou
- Department of Physics and Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida, 32306, USA
| | | | - Bernard Maigret
- CNRS, LORIA, Campus Scientifique, BP 239, Vandœuvre-lès-Nancy, 54506, France
| | | | - Anisah Ghoorah
- Department of Computer Science and Engineering, University of Mauritius, Reduit, Mauritius
| | - Mieczyslaw Torchala
- Biomolecular Modelling Laboratory, the Francis Crick Institute, Lincoln's Inn Fields Laboratory, London, WC2A 3LY, United Kingdom
| | - Raphaël A G Chaleil
- Biomolecular Modelling Laboratory, the Francis Crick Institute, Lincoln's Inn Fields Laboratory, London, WC2A 3LY, United Kingdom
| | - Paul A Bates
- Biomolecular Modelling Laboratory, the Francis Crick Institute, Lincoln's Inn Fields Laboratory, London, WC2A 3LY, United Kingdom
| | - Efrat Ben-Zeev
- G-INCPM, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Miriam Eisenstein
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Surendra S Negi
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas, 77555-0857
| | - Zhiping Weng
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts, 01605
| | - Thom Vreven
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts, 01605
| | - Brian G Pierce
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts, 01605
| | - Tyler M Borrman
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts, 01605
| | - Jinchao Yu
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University Paris-Saclay, CEA-Saclay, Gif-sur-Yvette, 91191, France
| | - Françoise Ochsenbein
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University Paris-Saclay, CEA-Saclay, Gif-sur-Yvette, 91191, France
| | - Raphaël Guerois
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University Paris-Saclay, CEA-Saclay, Gif-sur-Yvette, 91191, France
| | - Anna Vangone
- Bijvoet Center for Biomolecular Research, Faculty of Science - Chemistry, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - João P G L M Rodrigues
- Bijvoet Center for Biomolecular Research, Faculty of Science - Chemistry, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Gydo van Zundert
- Bijvoet Center for Biomolecular Research, Faculty of Science - Chemistry, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Mehdi Nellen
- Bijvoet Center for Biomolecular Research, Faculty of Science - Chemistry, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Li Xue
- Bijvoet Center for Biomolecular Research, Faculty of Science - Chemistry, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Ezgi Karaca
- Bijvoet Center for Biomolecular Research, Faculty of Science - Chemistry, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Adrien S J Melquiond
- Bijvoet Center for Biomolecular Research, Faculty of Science - Chemistry, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Koen Visscher
- Bijvoet Center for Biomolecular Research, Faculty of Science - Chemistry, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Panagiotis L Kastritis
- Bijvoet Center for Biomolecular Research, Faculty of Science - Chemistry, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Alexandre M J J Bonvin
- Bijvoet Center for Biomolecular Research, Faculty of Science - Chemistry, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Xianjin Xu
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, 65211
| | - Liming Qiu
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, 65211
| | - Chengfei Yan
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, 65211
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri, 65211
| | - Jilong Li
- Department of Computer Science, University of Missouri, Columbia, Missouri, 65211
| | - Zhiwei Ma
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, 65211
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri, 65211
| | - Jianlin Cheng
- Department of Computer Science, University of Missouri, Columbia, Missouri, 65211
- Informatics Institute, University of Missouri, Columbia, Missouri, 65211
| | - Xiaoqin Zou
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, 65211
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri, 65211
- Informatics Institute, University of Missouri, Columbia, Missouri, 65211
- Department of Biochemistry, University of Missouri, Columbia, Missouri, 65211
| | - Yang Shen
- Toyota Technological Institute at Chicago, 6045 S Kenwood Avenue, Chicago, Illinois, 60637
| | - Lenna X Peterson
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, 47907
| | - Hyung-Rae Kim
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, 47907
| | - Amit Roy
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, 47907
- Bioinformatics and Computational Biosciences Branch, Rocky Mountain Laboratories, National Institutes of Health, Hamilton, Montano 59840
| | - Xusi Han
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, 47907
| | | | - Daisuke Kihara
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, 47907
- Department of Computer Science, Purdue University, West Lafayette, IN, USA, 47907
| | - Xiaofeng Yu
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Germany
| | - Neil J Bruce
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Germany
| | - Jonathan C Fuller
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Germany
| | - Rebecca C Wade
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Germany
- Center for Molecular Biology (ZMBH), DKFZ-ZMBH Alliance, Heidelberg University, Heidelberg, Germany
- Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Heidelberg, Germany
| | - Ivan Anishchenko
- Center for Computational Biology, The University of Kansas, Lawrence, Kansas, 66047
| | - Petras J Kundrotas
- Center for Computational Biology, The University of Kansas, Lawrence, Kansas, 66047
| | - Ilya A Vakser
- Center for Computational Biology, The University of Kansas, Lawrence, Kansas, 66047
- Department of Molecular Biosciences, The University of Kansas, Lawrence, Kansas, 66047
| | - Kenichiro Imai
- Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST), Koto-Ku, Japan
| | - Kazunori Yamada
- Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST), Koto-Ku, Japan
| | - Toshiyuki Oda
- Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST), Koto-Ku, Japan
| | - Tsukasa Nakamura
- Graduate School of Frontier Sciences, the University of Tokyo, Kashiwa, Japan
| | - Kentaro Tomii
- Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST), Koto-Ku, Japan
- Graduate School of Frontier Sciences, the University of Tokyo, Kashiwa, Japan
| | - Chiara Pallara
- Joint BSC-CRG-IRB Research Program in Computational Biology, Barcelona Supercomputing Center, C/Jordi Girona 29, Barcelona, 08034, Spain
| | - Miguel Romero-Durana
- Joint BSC-CRG-IRB Research Program in Computational Biology, Barcelona Supercomputing Center, C/Jordi Girona 29, Barcelona, 08034, Spain
| | - Brian Jiménez-García
- Joint BSC-CRG-IRB Research Program in Computational Biology, Barcelona Supercomputing Center, C/Jordi Girona 29, Barcelona, 08034, Spain
| | - Iain H Moal
- Joint BSC-CRG-IRB Research Program in Computational Biology, Barcelona Supercomputing Center, C/Jordi Girona 29, Barcelona, 08034, Spain
| | - Juan Férnandez-Recio
- Joint BSC-CRG-IRB Research Program in Computational Biology, Barcelona Supercomputing Center, C/Jordi Girona 29, Barcelona, 08034, Spain
| | - Jong Young Joung
- Center for in-Silico Protein Science, Korea Institute for Advanced Study, Seoul, 130-722, Korea
| | - Jong Yun Kim
- Center for in-Silico Protein Science, Korea Institute for Advanced Study, Seoul, 130-722, Korea
| | - Keehyoung Joo
- Center for in-Silico Protein Science, Korea Institute for Advanced Study, Seoul, 130-722, Korea
- Center for Advanced Computation, Korea Institute for Advanced Study, Seoul, 130-722, Korea
| | - Jooyoung Lee
- Center for in-Silico Protein Science, Korea Institute for Advanced Study, Seoul, 130-722, Korea
- School of Computational Science, Korea Institute for Advanced Study, Seoul, 130-722, Korea
| | - Dima Kozakov
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Sandor Vajda
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
- Department of Chemistry, Boston University, Boston, Massachusetts
| | - Scott Mottarella
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - David R Hall
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Dmitri Beglov
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Artem Mamonov
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Bing Xia
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Tanggis Bohnuud
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Carlos A Del Carpio
- Institute of Biological Diversity, International Pacific Institute of Indiana, Bloomington, Indiana, 47401
- Drosophila Genetic Resource Center, Kyoto Institute of Technology, Ukyo-Ku, 616-8354, Japan
| | - Eichiro Ichiishi
- International University of Health and Welfare Hospital (IUHW Hospital), Asushiobara-City, Tochigi Prefecture, 329-2763, Japan
| | - Nicholas Marze
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, 21218
| | - Daisuke Kuroda
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, 21218
| | - Shourya S Roy Burman
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, 21218
| | - Jeffrey J Gray
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, 21218
- Program in Molecular Biophysics, Johns Hopkins University, Baltimore, Maryland, 21218
| | - Edrisse Chermak
- King Abdullah University of Science and Technology, Saudi Arabia
| | - Luigi Cavallo
- King Abdullah University of Science and Technology, Saudi Arabia
| | - Romina Oliva
- University of Naples "Parthenope", Napoli, Italy
| | - Andrey Tovchigrechko
- J. Craig Venter Institute, 9704 Medical Center Drive, Rockville, Maryland, 20850
| | - Shoshana J Wodak
- Departments of Biochemistry and Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
- VIB Structural Biology Research Center, VUB Pleinlaan 2, Brussels, 1050, Belgium.
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Chen X, Negi SS, Liao S, Gao V, Braun W, Dreskin SC. Conformational IgE epitopes of peanut allergens Ara h 2 and Ara h 6. Clin Exp Allergy 2016; 46:1120-1128. [PMID: 27238146 DOI: 10.1111/cea.12764] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 05/11/2016] [Accepted: 05/14/2016] [Indexed: 12/01/2022]
Abstract
BACKGROUND Cross-linking of IgE antibody by specific epitopes on the surface of mast cells is a prerequisite for triggering symptoms of peanut allergy. IgE epitopes are frequently categorized as linear or conformational epitopes. Although linear IgE-binding epitopes of peanut allergens have been defined, little is known about conformational IgE-binding epitopes. OBJECTIVE To identify clinically relevant conformational IgE epitopes of the two most important peanut allergens, Ara h 2 and Ara h 6, using phage peptide library. METHODS A phage 12mer peptide library was screened with allergen-specific IgE from 4 peanut-allergic patients. Binding of the mimotopes to IgE from a total of 29 peanut-allergic subjects was measured by ELISA. The mimotope sequences were mapped on the surface areas of Ara h 2 and Ara h 6 using EpiSearch. RESULTS Forty-one individual mimotopes were identified that specifically bind anti- Ara h 2/Ara h 6 IgE as well as rabbit anti-Ara h 2 and anti-Ara h 6 IgG. Sequence alignment showed that none of the mimotope sequences match a linear segment of the Ara h 2 or Ara h 6 sequences. EpiSearch analysis showed that all the mimotopes mapped to surface patches of Ara h 2 and Ara h 6. Eight of the mimotopes were recognized by more than 90% of the patients, suggesting immunodominance. Each patient had distinct IgE recognition patterns but the recognition frequency was not correlated to the concentration of peanut specific IgE or to clinical history. CONCLUSIONS The mimotopes identified in this study represent conformational epitopes. Identification of similar surface patches on Ara h 2 and Ara h 6 further underscores the similarities between these two potent allergens.
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Affiliation(s)
- Xueni Chen
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO
| | - Surendra S Negi
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Sumei Liao
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO
| | - Valerie Gao
- Molecular Cellular Developmental Biology, University of Colorado, Boulder, CO
| | - Werner Braun
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO
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Negi SS, Nagarkar NM. One step away from conquering polio eradication in India. Indian J Med Microbiol 2014; 32:199. [PMID: 24713917 DOI: 10.4103/0255-0857.129838] [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] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- S S Negi
- Department of Microbiology, All India Institute of Medical Sciences, Raipur, Chhattisgarh, India
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Lu W, Negi SS, Oberhauser AF, Braun W. Engineering proteins with enhanced mechanical stability by force-specific sequence motifs. Proteins 2012; 80:1308-15. [PMID: 22274941 DOI: 10.1002/prot.24027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 12/22/2011] [Accepted: 01/02/2012] [Indexed: 11/09/2022]
Abstract
Use of atomic force microscopy (AFM) has recently led to a better understanding of the molecular mechanisms of the unfolding process by mechanical forces; however, the rational design of novel proteins with specific mechanical strength remains challenging. We have approached this problem from a new perspective that generates linear physical-chemical properties (PCP) motifs from a limited AFM data set. Guided by our linear sequence analysis, we designed and analyzed four new mutants of the titin I1 domain with the goal of increasing the domain's mechanical strength. All four mutants could be cloned and expressed as soluble proteins. AFM data indicate that at least two of the mutants have increased molecular mechanical strength. This observation suggests that the PCP method is useful to graft sequences specific for high mechanical stability to weak proteins to increase their mechanical stability, and represents an additional tool in the design of novel proteins besides steered molecular dynamics calculations, coarse grained simulations, and ϕ-value analysis of the transition state.
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Affiliation(s)
- Wenzhe Lu
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-0857, USA
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15
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Tiwari R, Negi SS, Braun B, Braun W, Pomés A, Chapman MD, Goldblum RM, Midoro-Horiuti T. Validation of a phage display and computational algorithm by mapping a conformational epitope of Bla g 2. Int Arch Allergy Immunol 2011; 157:323-30. [PMID: 22123204 DOI: 10.1159/000330108] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 06/15/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Bla g 2, one of the major cockroach allergens, induces a strong IgE response against conformational epitopes, and on reexposure, sensitized individuals often display symptoms of allergic rhinitis and asthma. The aim of the current study was to perform a test of the efficacy of a modified phage display screening, characterization of selected phages and an automated algorithm, EpiSearch, in locating an important conformational epitope. METHODS The monoclonal antibody 7C11, which partially inhibits the binding of patient IgE antibodies to Bla g 2, was used to screen a random peptide phage library. After 3 rounds of panning, 32 phage clones were isolated and the amino acid sequences of their peptides were determined. The relative affinity and specificity of the binding of these peptides to 7C11 were tested in ELISAs. The amino acid composition of these peptides was then matched with clusters of residues on the surface of the 3-dimensional (3D) structure of Bla g 2, using our EpiSearch algorithm. RESULTS The amino acid sequences of the peptides on selected phages differed at only one position, occupied by 1 of 2 negatively charged residues. The two 12-mer sequences bound to 7C11 with similar avidity and specificity. There was good concordance between the residues in the 3D clusters identified from our phage display/computational method with the co-crystal structural analysis. CONCLUSION Conformational epitopes may be mapped through screening of clones from random peptide phage display libraries and EpiSearch.
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Affiliation(s)
- Ruby Tiwari
- Department of Pediatrics, Child Health Research Center, University of Texas Medical Branch, Galveston, TX 77555-0366, USA
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Garg A, Sasturkar SV, Sharma P, Pamecha V, Singh S, Negi SS, Sarin SK. 7 acute liver failure in giant cell hepatitis-successful adult-to-adult right lobe living-related liver transplantation. J Clin Exp Hepatol 2011; 1:136. [PMID: 25755336 PMCID: PMC3940304 DOI: 10.1016/s0973-6883(11)60144-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Negi SS, Grover SS, Rautela SS, Rawat DS, Gupta S, Khare S, Lal S, Rai A. Direct detection and serogroup characterization of Neisseria meningitidis from outbreak of meningococcal meningitis in Delhi. Iran J Microbiol 2010; 2:73-9. [PMID: 22347552 PMCID: PMC3279770] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND AND OBJECTIVES Rapid clinical manifestation/progression of the meningococcal meningitis and lacunae in conventional bacteriological test often encourages indiscriminate use of antibiotics much before the etiology is established. Accordingly this study was planned to evaluate ctrA PCR for rapid molecular detection. In addition, multiplex PCR and sequencing was done for serogroup prediction to provide essential epidemiological and laboratory evidence for decision makers of health department of the country for choosing appropriate vaccine and phylogenetic analysis to establish its lineage. MATERIALS AND METHODS 73 CSF samples, collected from equal number of suspected cases, were investigated by both bacteriological (microscopy, culture, LA and drug sensitivity testing) as well as molecular tests i.e. PCR targeting conserved ctrA gene, multiplex PCR for serogroup characterization and DNA sequencing. RESULTS ctrA PCR revealed sensitivity, specificity, positive predictive value and negative predictive values of 93.15%, 100%,100%, and 88.23% respectively. Multiplex PCR based genogrouping followed by DNA sequencing, BLAST and phylogenetic analysis revealed complete homology with earlier submitted Neisseria meningitidis serogroup A strain Z2491 to suggest the sole involvement of only serogroup A in the outbreak. Two strains showed resistance to cefuroxime, ciprofloxacin, nalidixic acid. Only one strain showed resistance to ciprofloxacin, emphasizing the need for a constant surveillance system. CONCLUSION These diagnostic molecular tools are of paramount importance in establishing etiology, serogrouping, and epidemiological surveillance especially in developing countries like India.
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Affiliation(s)
- SS Negi
- Biotechnology & Biochemistry Division,Corresponding author: Dr. Sanjay Singh Negi Address: Biotechnology & Biochemistry Division, National Centre for Disease Control (NCDC) (Previously NICD) 22-Shamnath marg, Delhi-54, India. Tel: +91-9899551119. E-mail:
| | - SS Grover
- Biotechnology & Biochemistry Division
| | | | - DS Rawat
- Biotechnology & Biochemistry Division
| | | | | | | | - A Rai
- Biotechnology & Biochemistry Division
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Negi SS, Sud R, Chaudhary A. Tubercular ileal stricture with enterolithiasis presenting as massive lower gastrointestinal bleed. Trop Gastroenterol 2010; 31:47-48. [PMID: 20860228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Affiliation(s)
- S S Negi
- Sir Ganga Ram Hospital, Rajinder Nagar, New Delhi, India
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Negi SS, Singh U, Gupta S, Khare S, Rai A, Lal S. Characterization of RPO B gene for detection of rifampicin drug resistance by SSCP and sequence analysis. Indian J Med Microbiol 2009; 27:226-30. [PMID: 19584503 DOI: 10.4103/0255-0857.45364] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
PURPOSE Because of the emergence of multidrug-resistant tuberculosis in recent times, the rapid detection of resistance to the first-line anti-tuberculosis drug rifampicin was felt worldwide. Accordingly, this study was conducted to evaluate the diagnostic potential of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) for checking its utility as a rapid screening test for determination of rifampicin drug resistance. MATERIALS AND METHODS A total of 34 isolates of Mycobacterium tuberculosis (M. tuberculosis) (22 rifampicin resistant, 11 rifampicin sensitive and one control H37Rv) strains were analysed by PCR-SSCP and DNA sequencing within the 157-bp region of the rpo B gene (Ala 500-Val 550). RESULTS Rifampicin resistance was detected successfully by PCR-SSCP in 20/22(90.90%) of rifampicin-resistant strains showing a total of nine different mutations in seven codon positions: codon 513 (CAA-->CCA), 516 (GAC-->GTC), 507 (GGC-->GAC), 526 (CAC-->GAC, TAC), 531 (TCG-->TTG, TGG), 522 (TCG-->TGG) and 533 (GTG-->CCG). Two rifampicin-resistant strains showed an identical PCR-SSCP pattern with the wild type H37Rv; 77.27% rifampicin-resistant strains showed a single point mutation and 9.09% had no mutation. Three rifampicin-resistant strains showed characteristic double mutations at codon positions 526 and 531. Sensitivity and specificity were calculated as 90.90% and 100%. CONCLUSIONS Rifampicin-resistant genotypes were mainly found in codon positions 516, 526 and 531. PCR-SSCP seems to be an efficacious method of predicting rifampicin resistance and substantially reduces the time required for susceptibility testing from 4 to 6 weeks to a few weeks.
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Affiliation(s)
- S S Negi
- National Institute of Communicable Diseases, Ministry of Health and FW, Government of India, 22-Shamnath Marg, Delhi, India
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20
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Abstract
Background: Precise determination of conformational epitopes of neutralizing antibodies represents a key step in the rational design of novel vaccines. A powerful experimental method to gain insights on the physical chemical nature of conformational epitopes is the selection of linear peptides that bind with high affinities to a monoclonal antibody of interest by phage display technology. However, the structural characterization of conformational epitopes from these mimotopes is not straightforward, and in the past the interpretation of peptide sequences from phage display experiments focused on linear sequence analysis to find a consensus sequence or common sequence motifs. Results: We present a fully automated search method, EpiSearch that predicts the possible location of conformational epitopes on the surface of an antigen. The algorithm uses peptide sequences from phage display experiments as input, and ranks all surface exposed patches according to the frequency distribution of similar residues in the peptides and in the patch. We have tested the performance of the EpiSearch algorithm for six experimental data sets of phage display experiments, the human epidermal growth factor receptor-2 (HER-2/neu), the antibody mAb Bo2C11 targeting the C2 domain of FVIII, antibodies mAb 17b and mAb b12 of the HIV envelope protein gp120, mAb 13b5 targeting HIV-1 capsid protein and 80R of the SARS coronavirus spike protein. In all these examples the conformational epitopes as determined by the X-ray crystal structures of the antibody-antigen complexes, were found within the highest scoring patches of EpiSearch, covering in most cases more than 50% residues of experimental observed conformational epitopes. Input options of the program include mapping of a single peptide or a set of peptides on the antigen structure, and the results of the calculation can be visualized on our interactive web server. Availability: Users can access the EpiSearch from our web server http://curie.utmb.edu/episearch.html
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Affiliation(s)
- Surendra S Negi
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston TX, 77555-0857, USA.
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Ivanciuc O, Schein CH, Garcia T, Oezguen N, Negi SS, Braun W. Structural analysis of linear and conformational epitopes of allergens. Regul Toxicol Pharmacol 2008; 54:S11-9. [PMID: 19121639 DOI: 10.1016/j.yrtph.2008.11.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2008] [Revised: 11/06/2008] [Accepted: 11/06/2008] [Indexed: 11/17/2022]
Abstract
In many countries regulatory agencies have adopted safety guidelines, based on bioinformatics rules from the WHO/FAO and EFSA recommendations, to prevent potentially allergenic novel foods or agricultural products from reaching consumers. We created the Structural Database of Allergenic Proteins (SDAP, http://fermi.utmb.edu/SDAP/) to combine data that had previously been available only as flat files on Web pages or in the literature. SDAP was designed to be user friendly, to be of maximum use to regulatory agencies, clinicians, as well as to scientists interested in assessing the potential allergenic risk of a protein. We developed methods, unique to SDAP, to compare the physicochemical properties of discrete areas of allergenic proteins to known IgE epitopes. We developed a new similarity measure, the property distance (PD) value that can be used to detect related segments in allergens with clinical observed cross-reactivity. We have now expanded this work to obtain experimental validation of the PD index as a quantitative predictor of IgE cross-reactivity, by designing peptide variants with predetermined PD scores relative to known IgE epitopes. In complementary work we show how sequence motifs characteristic of allergenic proteins in protein families can be used as fingerprints for allergenicity.
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Affiliation(s)
- Ovidiu Ivanciuc
- Sealy Center for Structural Biology and Molecular Biophysics, Departments of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-0857, USA
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Oezguen N, Zhou B, Negi SS, Ivanciuc O, Schein CH, Labesse G, Braun W. Comprehensive 3D-modeling of allergenic proteins and amino acid composition of potential conformational IgE epitopes. Mol Immunol 2008; 45:3740-7. [PMID: 18621419 PMCID: PMC2593650 DOI: 10.1016/j.molimm.2008.05.026] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Revised: 05/28/2008] [Accepted: 05/29/2008] [Indexed: 11/21/2022]
Abstract
Similarities in sequences and 3D structures of allergenic proteins provide vital clues to identify clinically relevant immunoglobulin E (IgE) cross-reactivities. However, experimental 3D structures are available in the Protein Data Bank for only 5% (45/829) of all allergens catalogued in the Structural Database of Allergenic Proteins (SDAP, http://fermi.utmb.edu/SDAP). Here, an automated procedure was used to prepare 3D-models of all allergens where there was no experimentally determined 3D structure or high identity (95%) to another protein of known 3D structure. After a final selection by quality criteria, 433 reliable 3D models were retained and are available from our SDAP Website. The new 3D models extensively enhance our knowledge of allergen structures. As an example of their use, experimentally derived "continuous IgE epitopes" were mapped on 3 experimentally determined structures and 13 of our 3D-models of allergenic proteins. Large portions of these continuous sequences are not entirely on the surface and therefore cannot interact with IgE or other proteins. Only the surface exposed residues are constituents of "conformational IgE epitopes" which are not in all cases continuous in sequence. The surface exposed parts of the experimental determined continuous IgE epitopes showed a distinct statistical distribution as compared to their presence in typical protein-protein interfaces. The amino acids Ala, Ser, Asn, Gly and particularly Lys have a high propensity to occur in IgE binding sites. The 3D-models will facilitate further analysis of the common properties of IgE binding sites of allergenic proteins.
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Affiliation(s)
- Numan Oezguen
- Department of Biochemistry and Molecular Biology and Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-0857, USA
| | - Bin Zhou
- Current address: Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive San Diego, CA 92121, USA
| | - Surendra S. Negi
- Department of Biochemistry and Molecular Biology and Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-0857, USA
| | - Ovidiu Ivanciuc
- Department of Biochemistry and Molecular Biology and Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-0857, USA
| | - Catherine H. Schein
- Department of Biochemistry and Molecular Biology and Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-0857, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-0857, USA
| | - Gilles Labesse
- CNRS-Universités Montpellier 1 & 2, UMR5048, Centre de Biochimie Structurale, 29, Rue de Navacelles, F-34090 Montpellier Cedex, France
- INSERM U554, Centre de Biochimie Structurale, 29, Rue de Navacelles, F-34090 Montpellier Cedex, France
| | - Werner Braun
- Department of Biochemistry and Molecular Biology and Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-0857, USA
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Negi SS, Carol AA, Pandya S, Braun W, Anderson LE. Co-localization of glyceraldehyde-3-phosphate dehydrogenase with ferredoxin-NADP reductase in pea leaf chloroplasts. J Struct Biol 2008; 161:18-30. [PMID: 17945509 PMCID: PMC2590647 DOI: 10.1016/j.jsb.2007.08.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Revised: 08/23/2007] [Accepted: 08/28/2007] [Indexed: 10/22/2022]
Abstract
In immunogold double-labeling of pea leaf thin sections with antibodies raised against ferredoxin-NADP reductase (EC 1.18.1.2, FNR) and antibodies directed against the A or B subunits of the NADP-linked glyceraldehyde-3-P dehydrogenase (GAPD) (EC 1.2.1.13), many small and large gold particles were found together over the chloroplasts. Nearest neighbor analysis of the distribution of the gold particles indicates that FNR and the NADP-linked GAPD are co-localized, in situ. This suggests that FNR might carry FADH2 or NADPH from the thylakoid membrane to GAPD, or that ferredoxin might carry electrons to FNR co-localized with GAPD in the stroma. Crystal structures of the spinach enzymes are available. When they are docked computationally, the proteins appear, as modeled, to be able to form at least two different complexes. One involves a single GAPD monomer and an FNR monomer (or dimer). The amino acid residues located at the putative interface are highly conserved on the chloroplastic forms of both enzymes. The other potential complex involves the GAPD A2B2 tetramer and an FNR monomer (or dimer). The interface residues are conserved in this model as well. Ferredoxin is able to interact with FNR in either complex.
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Affiliation(s)
- Surendra S. Negi
- Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Andrew A. Carol
- Department of Biological Sciences, University of Illinois—Chicago, 845 West Taylor, Chicago, IL 60607, USA
| | - Shivangi Pandya
- Department of Biological Sciences, University of Illinois—Chicago, 845 West Taylor, Chicago, IL 60607, USA
| | - Werner Braun
- Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Louise E. Anderson
- Department of Biological Sciences, University of Illinois—Chicago, 845 West Taylor, Chicago, IL 60607, USA
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Abstract
UNLABELLED A new web server, InterProSurf, predicts interacting amino acid residues in proteins that are most likely to interact with other proteins, given the 3D structures of subunits of a protein complex. The prediction method is based on solvent accessible surface area of residues in the isolated subunits, a propensity scale for interface residues and a clustering algorithm to identify surface regions with residues of high interface propensities. Here we illustrate the application of InterProSurf to determine which areas of Bacillus anthracis toxins and measles virus hemagglutinin protein interact with their respective cell surface receptors. The computationally predicted regions overlap with those regions previously identified as interface regions by sequence analysis and mutagenesis experiments. AVAILABILITY The InterProSurf web server is available at http://curie.utmb.edu/
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Affiliation(s)
- Surendra S Negi
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-0857, USA
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Negi SS, Braun W. Statistical analysis of physical-chemical properties and prediction of protein-protein interfaces. J Mol Model 2007; 13:1157-67. [PMID: 17828612 PMCID: PMC2628805 DOI: 10.1007/s00894-007-0237-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Accepted: 07/30/2007] [Indexed: 10/22/2022]
Abstract
We have developed a fully automated method, InterProSurf, to predict interacting amino acid residues on protein surfaces of monomeric 3D structures. Potential interacting residues are predicted based on solvent accessible surface areas, a new scale for interface propensities, and a cluster algorithm to locate surface exposed areas with high interface propensities. Previous studies have shown the importance of hydrophobic residues and specific charge distribution as characteristics for interfaces. Here we show differences in interface and surface regions of all physical chemical properties of residues as represented by five quantitative descriptors. In the current study a set of 72 protein complexes with known 3D structures were analyzed to obtain interface propensities of residues, and to find differences in the distribution of five quantitative descriptors for amino acid residues. We also investigated spatial pair correlations of solvent accessible residues in interface and surface areas, and compared log-odds ratios for interface and surface areas. A new scoring method to predict potential functional sites on the protein surface was developed and tested for a new dataset of 21 protein complexes, which were not included in the original training dataset. Empirically we found that the algorithm achieves a good balance in the accuracy of precision and sensitivity by selecting the top eight highest scoring clusters as interface regions. The performance of the method is illustrated for a dimeric ATPase of the hyperthermophile, Methanococcus jannaschii, and the capsid protein of Human Hepatitis B virus. An automated version of the method can be accessed from our web server at http://curie.utmb.edu/prosurf.html.
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Affiliation(s)
- Surendra S Negi
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555-0857, USA
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Kumar S, Zhao Y, Sun L, Negi SS, Halpert JR, Muralidhara BK. Rational engineering of human cytochrome P450 2B6 for enhanced expression and stability: importance of a Leu264->Phe substitution. Mol Pharmacol 2007; 72:1191-9. [PMID: 17715394 DOI: 10.1124/mol.107.039693] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Despite the emerging importance of human P450 2B6 in xenobiotic metabolism, thorough biochemical and biophysical characterization has been impeded as a result of low expression in Escherichia coli. Comparison with similar N-terminal truncated and C-terminal His-tagged constructs (rat P450 2B1dH, rabbit 2B4dH, and dog 2B11dH) revealed that P450 2B6dH showed the lowest thermal stability, catalytic tolerance to temperature, and chemical stability against guanidinium chloride-induced denaturation. Eleven P450 2B6dH mutants were rationally engineered based on sequence comparison with the three other P450 2B enzymes and the solvent accessibility of residues in the ligand-free crystal structure of P450 2B4dH. L198M, L264F, and L390P showed approximately 3-fold higher expression than P450 2B6dH. L264F alone showed enhanced stability against thermal and chemical denaturation compared with P450 2B6dH and was characterized further functionally. L264F showed similar preferential inhibition by pyridine over imidazole derivatives as P450 2B6dH. The Leu(264)-->Phe substitution did not alter the K(s) for inhibitors or the substrate benzphetamine, the K(m) for 7-ethoxy-4-(trifluoromethyl)coumarin, or the benzphetamine metabolite profiles. The enhanced stability and monodisperse nature of L264F made it suitable for isothermal titration calorimetry studies. Interaction of 1-benzylimidazole with L264F yielded a clear binding isotherm with a distinctly different thermodynamic signature from P450 2B4dH. The inhibitor docked differently in the binding pocket of a P450 2B6 homology model than in 2B4, highlighting the different chemistry of the active site of these two enzymes. Thus, L264F is a good candidate to further explore the unique structure-function relationships of P450 2B6 using X-ray crystallography and solution thermodynamics.
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Affiliation(s)
- Santosh Kumar
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-1031, USA.
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Lokesh GL, Muralidhara BK, Negi SS, Natarajan A. Thermodynamics of phosphopeptide tethering to BRCT: the structural minima for inhibitor design. J Am Chem Soc 2007; 129:10658-9. [PMID: 17685618 DOI: 10.1021/ja0739178] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- G L Lokesh
- Chemical Biology Program, Department of Pharmacology and Toxicology, Sealy Center for Structural Biology, University of Texas Medical Branch, Galveston, Texas 77555, USA
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Negi SS, Anand R, Pasha ST, Gupta S, Basir SF, Khare S, Lal S. Diagnostic potential of IS6110, 38kDa, 65kDa and 85B sequence-based polymerase chain reaction in the diagnosis of Mycobacterium tuberculosis in clinical samples. Indian J Med Microbiol 2007; 25:43-9. [PMID: 17377352 DOI: 10.4103/0255-0857.31061] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [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: 11/04/2022]
Abstract
PURPOSE The correlation between the presence of specific gene sequence of M. tuberculosis and specific diagnosis of clinical tuberculosis is not known. This study compared the results of polymerase chain reaction (PCR) amplification of M. tuberculosis specific DNA sequences (IS6110, 65kDa, 38kDa and mRNA coding for 85B protein) from different clinical samples of pulmonary and extrapulmonary tuberculosis. METHODS One hundred and seventy-two clinical samples from suspected tuberculosis patients were tested for smear examination, culture (LJ and rapid BACTEC 460 TB system) and PCR. PCR was performed with specific primers for the targets: IS6110, 65 kDa, 38 kDa and 85 B. RESULTS Each PCR test was found to have a much higher positivity than conventional test and BACTEC culture (P < 0.05). Smear positive samples (56) and the samples (36) showing positive results by conventional methods (smear and LJ medium culture) and BACTEC were found to be positive by all PCR protocols. No significant difference was found between the four PCR protocols (P> 0.05). The primer specific for amplifying the 123bp IS6110 fragment gave the highest positivity (83%), followed by 65kDa, 38kDa and 85B RT-PCR in descending order. CONCLUSIONS These data suggest that the presence of IS6110 correlates more closely with the diagnosis of clinical tuberculosis than that of 65kDa, 38kDa and 85B proteins.
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Affiliation(s)
- S S Negi
- Tuberculosis Laboratory, Microbiology Division, National Institute of Communicable Diseases, New Delhi, India
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Abstract
Conformational flexibility and cooperativity in ligand recognition are two key aspects of the catalytic diversity of cytochrome P450 enzymes. In this study, we dissect the ligand binding stoichiometry and energetics of the soluble bacterial P450eryF by isothermal titration calorimetry (ITC) using three allosteric and two non-allosteric ligands of diverse chemistry. Complementary spectral binding studies and sequential, two-ligand docking simulations were performed to help assign the binding sites. Binding of 4-phenylpyridine (4-PP) or 4-(4-chlorophenyl)imidazole (4-CPI) showed 1:1 stoichiometry in ITC, consistent with the lack of cooperativity observed in spectral binding studies. The larger ligands 9-aminophenanthrene (9-AP), 1-pyrenebutanol (1-PB), and alpha-naphthoflavone (ANF) show cooperative spectral binding and yielded 2:1 stoichiometry. The associated thermodynamic parameters for the sites were calculated using a sequential binding mechanism. The binding constant (KD) for the first site was almost two times lower than that of the second site for all three compounds. Ligand binding at site 1 was entropically favored, whereas binding at site 2 was weak and entropically unfavorable. Simulations showed that two molecules of 9-AP, ANF or 1-PB can be adequately docked to two individual sub-sites within a large binding pocket. The absence of hydrophobic tethering and ligand stacking are consistent with the single low affinity binding site observed for 4-CPI and 4-PP. Competitive binding studies with P450eryF preloaded with either 1-PB or ANF showed a decrease in the affinities for 9-AP at both the sites, with large entropy-enthalpy compensation, indicating the ability of the binding pocket to accommodate two ligands of diverse chemistry and enable cooperativity.
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Affiliation(s)
- B K Muralidhara
- Department of Pharmacology and Toxicology, and Sealy Center for Structural Biology, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555, USA.
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Negi SS, Anand R, Pasha ST, Gupta S, Basir SF, Khare S, Lal S. DIAGNOSTIC POTENTIAL OF IS6110, 38KDA, 65KDA AND 85B SEQUENCE-BASED POLYMERASE CHAIN REACTION IN THE DIAGNOSIS OF MYCOBACTERIUM TUBERCULOSIS IN CLINICAL SAMPLES. Indian J Med Microbiol 2007. [DOI: 10.1016/s0255-0857(21)02233-7] [Citation(s) in RCA: 4] [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: 11/29/2022]
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Negi SS, Anand R, Basir SF, Pasha ST, Gupta S, Khare S, Lal S. Protein antigen b (Pab) based PCR test in diagnosis of pulmonary and extra-pulmonary tuberculosis. Indian J Med Res 2006; 124:81-8. [PMID: 16926461] [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: 05/11/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Diagnosis of tuberculosis (TB) is largely based on microscopy and culture examination which are either less sensitive, or time consuming. In the present study a PCR (polymerase chain reaction) test based on DNA sequence coding for a 38-kilodalton protein antigen b (Pab) ,specific for Mycobacterium tuberculosis was compared with Ziehl-Neelsen (ZN) stained AFB (acid fast bacilli) smear examination, culture based on conventional Lowenstein-Jensen (LJ) medium and radiometric BACTEC 460 system for the diagnosis of TB using clinical samples obtained from pulmonary and extra-pulmonary cases of TB. METHODS Clinical samples obtained from 168 patients of suspected TB (pulmonary and extrapulmonary) were subjected to ZN smear examination, LJ culture, radiometric BACTEC culture and a PCR test by amplifying 419 bp sequence coding for Pab, a glycoprotein of molecular weight 38 kDa. RESULTS A significant difference was seen in the sensitivity of different tests, the figures being 74.2 per cent for PCR test, 53.4 per cent for BACTEC culture, 47.1 per cent for LJ medium based culture and 35.2 per cent for ZN smear examination (P<0.05). However, there was no significant difference between different tests as far as specificity was concerned. PCR test sensitivity in pulmonary and extra-pulmonary clinical samples were 74.3 and 71.5 per cent respectively, being significantly higher (P<0.05) when compared with sensitivity of other tests. The mean detection time for M. tuberculosis was 24.0 days by LJ media culture, 12.8 days by BACTEC culture and less than 1 day by smear examination and PCR test. INTERPRETATION AND CONCLUSION PCR test is more sensitive than ZN smear examination, LJ medium culture and BACTEC culture for diagnosing TB in pulmonary and extra-pulmonary clinical samples.
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Affiliation(s)
- S S Negi
- National Institute of Communicable Diseases, Delhi, India
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Negi SS, Kolokoltsov AA, Schein CH, Davey RA, Braun W. Determining functionally important amino acid residues of the E1 protein of Venezuelan equine encephalitis virus. J Mol Model 2006; 12:921-9. [PMID: 16607494 DOI: 10.1007/s00894-006-0101-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2005] [Accepted: 01/05/2006] [Indexed: 10/24/2022]
Abstract
A new method for predicting interacting residues in protein complexes, InterProSurf, was applied to the E1 envelope protein of Venezuelan equine encephalitis (VEEV). Monomeric and trimeric models of VEEV-E1 were constructed with our MPACK program, using the crystal structure of the E1 protein of Semliki forest virus as a template. An alignment of the E1 sequences from representative alphavirus sequences was used to determine physical chemical property motifs (likely functional areas) with our PCPMer program. Information on residue variability, propensity to be in protein interfaces, and surface exposure on the model was combined to predict surface clusters likely to interact with other viral or cellular proteins. Mutagenesis of these clusters indicated that the predictions accurately detected areas crucial for virus infection. In addition to the fusion peptide area in domain 2, at least two other surface areas play an important role in virus infection. We propose that these may be sites of interaction between the E1-E1 and E1-E2 subdomains of the envelope proteins that are required to assemble the functional unit. The InterProSurf method is, thus, an important new tool for predicting viral protein interactions. These results can aid in the design of new vaccines against alphaviruses and other viruses.
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Affiliation(s)
- Surendra S Negi
- Sealy Center for Structural Biology, Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-0857, USA
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Negi SS, Gupta S, Khare S, Lal S. Comparison of various microbiological tests including polymerase chain reaction for the diagnosis of osteoarticular tuberculosis. Indian J Med Microbiol 2005; 23:245-8. [PMID: 16327120] [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: 05/05/2023]
Abstract
PURPOSE To evaluate the utility of the polymerase chain reaction (PCR) test for diagnosing osteoarticular tuberculosis (TB). METHODS Clinical samples (synovial tissue and synovial fluid) obtained from 23 cases of suspected osteoarticular tuberculosis were subjected to Ziehl Neelsen (ZN) smear examination, radiometric BACTEC culture and PCR test for tuberculosis by amplifying 65 kDa antigen coding region of Mycobacterium tuberculosis (M.tb) genome. RESULTS PCR test was found to be much sensitive than the ZN smear examination and BACTEC culture (p<0.05) in the diagnosis of osteoarticular TB. In synovial fluid samples, PCR was positive in 73.9%, ZN smear examination in 17.39% and BACTEC culture in 39.13% of cases. The positivities were relatively lower with synovial tissue samples, the corresponding figures being 60.8, 8.6 and 26.08% respectively. Moreover, on combining the results of synovial fluid and tissues, the corresponding figures further increased to 78.2, 21.7 and 43.3% respectively. Further, sensitivity and specificity for PCR employing BACTEC culture as the "gold standard" was 100% respectively. Using BACTEC culture, the earliest positivity was seen in three days using synovial tissue specimen and 13 days with synovial fluid, the average detection times being 23.2 days and 32.6 days respectively. On the other hand, PCR test gave a positive result within 24 hours. CONCLUSIONS PCR test was shown to be much more sensitive than ZN smear examination and BACTEC culture test for diagnosing osteoarticular tuberculosis.
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Affiliation(s)
- S S Negi
- Microbiology Division, National Institute of communicable Diseases, New Delhi-110 054, India
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Negi SS, Gupta S, Khare S, Lal S. COMPARISON OF VARIOUS MICROBIOLOGICAL TESTS INCLUDING POLYMERASE CHAIN REACTION FOR THE DIAGNOSIS OF OSTEOARTICULAR TUBERCULOSIS. Indian J Med Microbiol 2005. [DOI: 10.1016/s0255-0857(21)02529-9] [Citation(s) in RCA: 3] [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: 10/21/2022]
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Negi SS, Khan SFB, Gupta S, Pasha ST, Khare S, Lal S. Comparison of the conventional diagnostic modalities, bactec culture and polymerase chain reaction test for diagnosis of tuberculosis. Indian J Med Microbiol 2005; 23:29-33. [PMID: 15928418 DOI: 10.4103/0255-0857.13869] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [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: 11/04/2022]
Abstract
PURPOSE To evaluate the performance of 65 kDa antigen based PCR assay in clinical samples obtained from pulmonary and extrapulmonary cases of tuberculosis. METHODS One hundred and fifty six samples were processed for detection of Mycobacterium tuberculosis by ZN smear examination, LJ medium culture, BACTEC radiometric culture and PCR tests. RESULTS A significant difference was seen in the sensitivities of different tests, the figures being 74.4% for PCR test, 33.79% for ZN smear examination, 48.9% for LJ culture and 55.8% for BACTEC culture (P< 0.05). However, there was no significant difference (P>0.05) as far as specificity of different tests was concerned. PCR test sensitivity in pulmonary and extrapulmonary clinical samples were 72.7% and 75.9% respectively and found to be significantly higher (P< 0.05) when compared with those of other tests. The mean detection time for M.tuberculosis was 24.03 days by LJ medium culture, 12.89 days by BACTEC culture and less than one day by PCR test. CONCLUSIONS PCR is a rapid and sensitive method for the early diagnosis of pulmonary and extrapulmonary tuberculosis.
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Affiliation(s)
- S S Negi
- Department of Microbiology, National Institute of Communicable Diseases, New Delhi 110 054, India
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Negi SS, Khan SFB, Gupta S, Pasha ST, Khare S, Lal S. COMPARISON OF THE CONVENTIONAL DIAGNOSTIC MODALITIES, BACTEC CULTURE AND POLYMERASE CHAIN REACTION TEST FOR DIAGNOSIS OF TUBERCULOSIS. Indian J Med Microbiol 2005. [DOI: 10.1016/s0255-0857(21)02708-0] [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: 10/21/2022]
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Abstract
We describe a case of benign signet ring cell change in the gallbladder mucosa. On histopathological examination of H&E-stained sections, the gallbladder epithelium showed multilayering. The epithelial cells were large, columnar to polygonal with a small round basal or eccentric nucleus and vacuolated cytoplasm, giving them a signet ring appearance. There was no nuclear atypia, hyperchromatism or mitotic activity. The cells showed uniform positivity with mucicarmine, PAS and Alcian blue stains. The cytoplasmic vacuolations were negative for fat stains (Oil red O and Sudan IV). On immunohistochemistry, the cells showed positivity with antibodies for pancytokeratin (PCK) and epithelial membrane antigen (EMA). A diagnosis of benign signet ring cell change with multilayering in the gall bladder mucosa was made. Thoroughly reviewing the literature, we found only one case of benign signet ring cell aggregates in the gallbladder mucosa documented earlier. The lesion is hereby reported because of the unique histomorphology and the diagnostic dilemma which can occur as a malignant change in situ has to be excluded.
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Affiliation(s)
- V S Suri
- Department of Pathology, G.B Pant Hospital, New Delhi, India.
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Chaudhary A, Negi SS, Puri SK, Narang P. Comparison of magnetic resonance cholangiography and percutaneous transhepatic cholangiography in the evaluation of bile duct strictures after cholecystectomy. Br J Surg 2002; 89:433-6. [PMID: 11952583 DOI: 10.1046/j.0007-1323.2002.02066.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [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: 11/20/2022]
Abstract
BACKGROUND Percutaneous transhepatic cholangiography (PTC) has been the preferred investigation to delineate the anatomy of the biliary tract in a patient with a bile duct stricture after cholecystectomy. Recently magnetic resonance cholangiography (MRC) has been described to evaluate the obstructed biliary tract. This paper reports a comparison of MRC with PTC in evaluating patients with an iatrogenic bile duct stricture. METHODS This was a prospective study of 26 patients who had surgery for a bile duct stricture after cholecystectomy. Before operation all patients underwent both MRC and PTC, the results of which were compared with the intraoperative findings. RESULTS Both PTC and MRC were comparable with regard to image quality, detection of intrahepatic bile duct dilatation, assessment of the level of injury and detection of abnormalities such as intraduct calculi, cholangitic liver abscesses and atrophy of liver lobes. MRC provided additional information in four patients, including detection of associated fluid collections (n = 3) and portal hypertension (n = 1). In eight patients more than one puncture had to be performed during PTC to delineate the complete anatomy. CONCLUSION MRC is an accurate and non-invasive imaging procedure for preoperative evaluation of patients with a bile duct injury after cholecystectomy, and is capable of providing additional information which may not be available with PTC.
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Affiliation(s)
- A Chaudhary
- Departments of Gastrointestinal Surgery and Radiology, Gobind Ballabh Pant Hospital, New Delhi, India
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Negi SS, Sachdev AK, Bhojwani R, Singh S, Kumar N. Experience of surgical management of pseudo-aneurysms of branches of the coeliac axis in a North Indian Hospital. Trop Gastroenterol 2002; 23:97-100. [PMID: 12632981] [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] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
BACKGROUND Bleeding splanchnic artery pseudo-aneurysm is a rare but frequently fatal complication that can be successfully managed by angiographic embolization. However, certain patients because of hemodynamic instability, non-availability of technique or angiographic failure may require primary surgical intervention. METHOD Retrospective review of 13 patients presenting with exsanguinating hemorrhage from ruptured pseudo-aneurysm arising from branches of coeliac axis, managed surgically in absence of angiographic embolization. RESULTS Splenic artery was most commonly involved (n = 7) followed by hepatic (n = 3), gastroduodenal (n = 2) and left gastric artery (n = 1). The most common underlying aetiology was pancreatitis (n = 8, acute = 2; chronic = 6) followed by iatrogenic (n = 3), liver abscess (n = 1) and gastric ulcer (n = 1). Seven patients presented with upper gastrointestinal (GI) bleed, while 2 each with lower GI bleed, haemobilia and bleeding through tube drains. CT-scan accurately demonstrated the pseudo-aneurysm in 11 (84.6%) patients and additionally demonstrated the underlying pathology. The surgical management chiefly consisted of ligation of offending vessel and additional procedures directed at primary pathology. Overall, 77% patients had a favourable outcome while 23% died consequent to ongoing hemorrhage. CONCLUSION Pseudo-aneurysm involving the branches of coeliac axis most commonly arises as a result of pancreatitis and affects splenic artery. CT-scan accurately demonstrates pseudo-aneurysm and associated pathology in majority of cases. Primary surgical management in the presence of hemodynamic instability and non-availability of angiographic embolization is a viable alternative.
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Affiliation(s)
- S S Negi
- G.B. Pant Hospital, University of Delhi, New Delhi-110 002
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Negi SS, Ramaswamy R. Critical states and fractal attractors in fractal tongues: localization in the Harper map. Phys Rev E Stat Nonlin Soft Matter Phys 2001; 64:045204. [PMID: 11690079 DOI: 10.1103/physreve.64.045204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2000] [Revised: 08/31/2000] [Indexed: 05/23/2023]
Abstract
Localized states of Harper's equation correspond to strange nonchaotic attractors in the related Harper mapping. In parameter space, these fractal attractors with nonpositive Lyapunov exponents occur in fractally organized tongue-like regions which emanate from the Cantor set of eigenvalues on the critical line epsilon=1. A topological invariant characterizes wave functions corresponding to energies in the gaps in the spectrum. This permits a unique integer labeling of the gaps and also determines their scaling properties as a function of potential strength.
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Affiliation(s)
- S S Negi
- School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110 067, India
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Sandhu BS, Kumar N, Sachdeva AK, Negi SS, Sridhar S, Malhotra V, Lamba GS, Puri AS. Paraganglionoma of extrahepatic biliary tract causing obstructive jaundice. Indian J Gastroenterol 2000; 19:141-2. [PMID: 10918729] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We report a young woman with paraganglionoma arising from the extrahepatic bile duct presenting with acute obstructive jaundice. The patient underwent excision of the gall bladder and extrahepatic bile duct with the tumor, and Roux-en-Y hepaticojejunostomy. She is asymptomatic 9 months later, with normal biochemical investigations and imaging.
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Affiliation(s)
- B S Sandhu
- Department of Gastroenterology, G B Pant Hospital, New Delhi
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Singh RN, Negi SS, Sahay AK, Singh A, Varughese KO, Walia AK. Mirage formation in the thermal region. Appl Opt 1994; 33:3279-3280. [PMID: 20885699 DOI: 10.1364/ao.33.003279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Formation of a mirage in the 8-12-µm band has been observed with a high-resolution thermal camera designed and developed by us. Thermal imagery recorded under actual field conditions is presented to illustrate the mirage phenomenon. Further analysis is in progress to estimate the effect of mirages in this waveband for civil and military applications.
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Makkar HP, Sharma OP, Dawra RK, Negi SS. A method for removal of interference by ammonium sulphate in protein assay by Lowry's method. Indian J Biochem Biophys 1983; 20:306-8. [PMID: 6676164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Abstract
A method for microbial protein determination based on Lowry's assay was devised. Differential centrifugation was used to separate bacterial cells from rumen liquor. Proteins from cells were released by suspending in .25 N sodium hydroxide and heating in boiling water bath for 10 min. Protein was determined by the Folin phenol method. The method is simple, accurate, reproducible, sensitive, specific, brief, and can be performed with small amount of rumen liquor (5 ml). A large number of samples can be handled conveniently.
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Abstract
Lantana toxicity of guinea pigs elicited an increase in hematocrit, erythrocyte and leukocyte number, hemoglobin, urea-nitrogen and bilirubin contents in the blood of the affected animals. Most of the bilirubin was present in the conjugated form. Enzyme activities of glutamic oxaloacetic transaminase, acid phosphatase, lactate dehydrogenase, glutamate dehydrogenase, sorbitol dehydrogenase in the blood plasma of affect animals exhibited a marked increase. Acid phosphatase activity was inhibited by tartrate. Enzyme activity of alkaline phosphatase remained unchanged while that of glutamic pyruvic transaminase showed a marginal decrease.
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Vaid J, Dawra RK, Sharma OP, Negi SS. Chronic aflatoxicosis in cattle. Vet Hum Toxicol 1981; 23:436-8. [PMID: 7336570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Pathological, hematological and plasma enzymatic studies were made on milk cattle affected by chronic aflatoxicosis caused by the prolonged feeding of concentrate feed mixtures containing contaminated groundnut cake having aflatoxin B1 (110 ug/kg groundnut cake at the time of sampling), B2, G1 and G2. Clinical and necropsy observations on liver included proliferation of connective tissue along portal triads leaving small group of hepatocytes intact. Liver function tests showed liver damage in three of the four affected animals studied.
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Abstract
Lantana poisoning has been taking a heavy toll of livestock year after year. All aspects of the problem are reviewed. Lantana poisoning in cattle, sheep, buffalo, and guinea pigs caused obstructive jaundice, photosensitization, and rise in serum glutamicoxaloaetic transaminase activity. The symptoms could be reproduced in sheep by administration of purified Lantadene A. Liver and kidneys are the most affected organs during lantana poisoning. Intoxication of guinea pigs with Lantana camara leads to marked alterations in major tissue constituents in liver an kidneys. Hepatic and renal xanthine oxidase activity is also elevated during lantana poisoning. No antidote is available against the toxic section of Lantana camara. Symptomatic treatments have been proposed with limited success. Knowledge of the biochemical mechanism of lantana intoxication at the cellular, subcellular, and molecular levels is essential in order to evolve a successful antidote and more rational therapy during lantana intoxication.
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Abstract
Acetohydroxamic acid at a concentration of 1 X 10(-6) M, 6 X 10(-5) M, and 1 X 10(-3) M inhibited urease of intact rumen microbes in vitro by 11%, 50%, and 74%. Inhibition of rumen urease by the acid reached equilibrium state, unlike jack bean urease. Inhibition was maximum over a broad range of pH (8 to 10) and it did not resemble the pH activity profile of rumen urease. Sulfhydryl compounds did not reverse the inhibition; however, addition of these compounds prior to acetohydroxamic acid addition prevented inhibition. The nature of inhibition was noncompetitive with inhibitor constant 4.8 X 10(-5) M. Acetohydroxamic acid at a concentration that produced 50% urease inhibition did not affect rumen cellulase and proteolytic enzymes in vitro. The complex of acetohydroxamic acid-rumen urease is dissociable on dialysis.
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Abstract
Oral administration of lantana leaf powder to guinea pigs caused a decrease in hepatic and renal tissue dry weight, DNA and protein contents. Total carbohydrate content decreased in liver but was not affected in the kidneys. RNA content (as a ratio of tissue dry weight) showed an increase in both liver and kidneys. Lipid content of liver tissue increased while it decreased in the kidneys. Relative amounts of protein, DNA and RNA showed significant alterations in both the tissues.
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Abstract
Clinical observations on four male cow calves and three other lantana poisoned animals under field conditions have been made along with hematological studies, including observations on plasma bilirubin content and osmotic fragility of erythrocytes. Four healthy male cow calves served as control. Five clinically advanced cases succumbed within 1 to 10 days of observation. Hematocrit values in four of the seven affected animals were abnormally high. The total plasma bilirubin content in the fatal cases was of the order of 5 to 50 times the normal value while, in calves that recovered, it was not more than 3 times. The osmotic fragility of erythrocytes was measured by the rate of hemolysis in decreasing concentrations of saline. The erythrocytes of normal animals resisted hemolysis till the saline concentration was lowered to 0.60%, and it was complete at the low saline concentration of 0.30%. However, in lantana poisoned animals, hemolysis started even in 0.72% saline and was complete at a saline concentration of 0.44%. The hemolysis curves of animals that died were far removed from the normal, but those of the calves that recovered and the one that died but had the lowest bilirubin content closely approached the normal curve.
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