1
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Lei R, Kim W, Lv H, Mou Z, Scherm MJ, Schmitz AJ, Turner JS, Tan TJC, Wang Y, Ouyang WO, Liang W, Rivera-Cardona J, Teo C, Graham CS, Brooke CB, Presti RM, Mok CKP, Krammer F, Dai X, Ellebedy AH, Wu NC. Leveraging vaccination-induced protective antibodies to define conserved epitopes on influenza N2 neuraminidase. Immunity 2023; 56:2621-2634.e6. [PMID: 37967533 PMCID: PMC10655865 DOI: 10.1016/j.immuni.2023.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 07/19/2023] [Accepted: 10/10/2023] [Indexed: 11/17/2023]
Abstract
There is growing appreciation for neuraminidase (NA) as an influenza vaccine target; however, its antigenicity remains poorly characterized. In this study, we isolated three broadly reactive N2 antibodies from the plasmablasts of a single vaccinee, including one that cross-reacts with NAs from seasonal H3N2 strains spanning five decades. Although these three antibodies have diverse germline usages, they recognize similar epitopes that are distant from the NA active site and instead involve the highly conserved underside of NA head domain. We also showed that all three antibodies confer prophylactic and therapeutic protection in vivo, due to both Fc effector functions and NA inhibition through steric hindrance. Additionally, the contribution of Fc effector functions to protection in vivo inversely correlates with viral growth inhibition activity in vitro. Overall, our findings advance the understanding of NA antibody response and provide important insights into the development of a broadly protective influenza vaccine.
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Affiliation(s)
- Ruipeng Lei
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Wooseob Kim
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Microbiology, Korea University College of Medicine, Seoul 02841, Korea
| | - Huibin Lv
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Zongjun Mou
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Michael J Scherm
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Aaron J Schmitz
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Jackson S Turner
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Timothy J C Tan
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yiquan Wang
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Wenhao O Ouyang
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Weiwen Liang
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Joel Rivera-Cardona
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Chuyun Teo
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Claire S Graham
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Christopher B Brooke
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Rachel M Presti
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA; Center for Vaccines and Immunity to Microbial Pathogens, Washington University School of Medicine, Saint Louis, MO 63110, USA; The Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Chris K P Mok
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR, China; Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China; S.H. Ho Research Centre for Infectious Diseases, The Chinese University of Hong Kong, Hong Kong SAR, China.
| | - Florian Krammer
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Pathology, Molecular and Cell Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Center for Vaccine Research and Pandemic Preparedness (C-VARPP), Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Xinghong Dai
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106, USA.
| | - Ali H Ellebedy
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA; Center for Vaccines and Immunity to Microbial Pathogens, Washington University School of Medicine, Saint Louis, MO 63110, USA; The Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, Saint Louis, MO 63110, USA.
| | - Nicholas C Wu
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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2
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Jaiswal D, Verma S, Nair DT, Salunke DM. Antibody multispecificity: A necessary evil? Mol Immunol 2022; 152:153-161. [DOI: 10.1016/j.molimm.2022.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/20/2022] [Accepted: 10/24/2022] [Indexed: 11/09/2022]
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3
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Guo Z, Wilson JR, York IA, Stevens J. Biosensor-based epitope mapping of antibodies targeting the hemagglutinin and neuraminidase of influenza A virus. J Immunol Methods 2018; 461:23-29. [PMID: 30053389 DOI: 10.1016/j.jim.2018.07.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 03/21/2018] [Accepted: 07/23/2018] [Indexed: 01/04/2023]
Abstract
Characterization of the epitopes on antigen recognized by monoclonal antibodies (mAb) is useful for the development of therapeutic antibodies, diagnostic tools, and vaccines. Epitope mapping also provides functional information for sequence-based repertoire analysis of antibody response to pathogen infection and/or vaccination. However, development of mapping strategies has lagged behind mAb discovery. We have developed a site-directed mutagenesis approach that can be used in conjunction with bio-layer interferometry (BLI) biosensors to map mAb epitopes. By generating a panel of single point mutants in the recombinant hemagglutinin (HA) and neuraminidase (NA) proteins of influenza A viruses, we have characterized the epitopes of hundreds of mAbs targeting the H1 and H3 subtypes of HA and the N9 subtype of NA.
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Affiliation(s)
- Zhu Guo
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jason R Wilson
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA; CNI Advantage, LLC, Norman, OK, USA
| | - Ian A York
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA.
| | - James Stevens
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA
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4
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Wilson JR, Guo Z, Reber A, Kamal RP, Music N, Gansebom S, Bai Y, Levine M, Carney P, Tzeng WP, Stevens J, York IA. An influenza A virus (H7N9) anti-neuraminidase monoclonal antibody with prophylactic and therapeutic activity in vivo. Antiviral Res 2016; 135:48-55. [PMID: 27713074 DOI: 10.1016/j.antiviral.2016.10.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 09/16/2016] [Accepted: 10/03/2016] [Indexed: 12/09/2022]
Abstract
Zoonotic A(H7N9) avian influenza viruses emerged in China in 2013 and continue to be a threat to human public health, having infected over 800 individuals with a mortality rate approaching 40%. Treatment options for people infected with A(H7N9) include the use of neuraminidase (NA) inhibitors. However, like other influenza viruses, A(H7N9) can become resistant to these drugs. The use of monoclonal antibodies is a rapidly developing strategy for controlling influenza virus infection. Here we generated a murine monoclonal antibody (3c10-3) directed against the NA of A(H7N9) and show that prophylactic systemic administration of 3c10-3 fully protected mice from lethal challenge with wild-type A/Anhui/1/2013 (H7N9). Further, post-infection treatment with a single systemic dose of 3c10-3 at either 24, 48 or 72 h post A(H7N9) challenge resulted in both dose- and time-dependent protection of up to 100% of mice, demonstrating therapeutic potential for 3c10-3. Epitope mapping revealed that 3c10-3 binds near the enzyme active site of NA, and functional characterization showed that 3c10-3 inhibits the enzyme activity of NA and restricts the cell-to-cell spread of the virus in cultured cells. Affinity analysis also revealed that 3c10-3 binds equally well to recombinant NA of wild-type A/Anhui/1/2013 and to a variant NA carrying a R289K mutation known to infer NAI resistance. These results suggest that 3c10-3 has the potential to be used as a therapeutic to treat A(H7N9) infections either as an alternative to, or in combination with, current NA antiviral inhibitors.
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Affiliation(s)
- Jason R Wilson
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA; Carter Consulting, Inc., Atlanta, GA, USA
| | - Zhu Guo
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Adrian Reber
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Ram P Kamal
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA; Battelle Memorial Institute, Atlanta, GA, USA
| | - Nedzad Music
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA; Battelle Memorial Institute, Atlanta, GA, USA
| | - Shane Gansebom
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA; Carter Consulting, Inc., Atlanta, GA, USA
| | - Yaohui Bai
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Min Levine
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Paul Carney
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Wen-Pin Tzeng
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - James Stevens
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Ian A York
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA.
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5
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Jagusiak A, Konieczny L, Krol M, Marszalek P, Piekarska B, Piwowar P, Roterman I, Rybarska J, Stopa B, Zemanek G. Intramolecular immunological signal hypothesis revived--structural background of signalling revealed by using Congo Red as a specific tool. Mini Rev Med Chem 2015; 14:1104-13. [PMID: 25429660 PMCID: PMC4440395 DOI: 10.2174/1389557514666141127150803] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 10/11/2014] [Accepted: 11/11/2014] [Indexed: 11/22/2022]
Abstract
Micellar structures formed by self-assembling Congo red molecules bind to proteins penetrating into functionrelated
unstable packing areas. Here, we have used Congo red - a supramolecular protein ligand to investigate how the
intramolecular structural changes that take place in antibodies following antigen binding lead to complement activation.
According to our findings, Congo red binding significantly enhances the formation of antigen-antibody complexes. As a
result, even low-affinity transiently binding antibodies can participate in immune complexes in the presence of Congo
red, although immune complexes formed by these antibodies fail to trigger the complement cascade. This indicates that
binding of antibodies to the antigen may not, by itself, fulfill the necessary conditions to generate the signal which
triggers effector activity. These findings, together with the results of molecular dynamics simulation studies, enable us to
conclude that, apart from the necessary assembling of antibodies, intramolecular structural changes generated by
strains which associate high- affinity bivalent antibody fitting to antigen determinants are also required to cross the
complement activation threshold.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - G Zemanek
- Department of Bioinformatics and Telemedicine, Jagiellonian University, Medical College, Lazarza 16, 31- 530 Krakow, Poland..
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6
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Garman EF. Antiviral adhesion molecular mechanisms for influenza: W. G. Laver's lifetime obsession. Philos Trans R Soc Lond B Biol Sci 2015; 370:20140034. [PMID: 25533092 PMCID: PMC4275904 DOI: 10.1098/rstb.2014.0034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Infection by the influenza virus depends firstly on cell adhesion via the sialic-acid-binding viral surface protein, haemagglutinin, and secondly on the successful escape of progeny viruses from the host cell to enable the virus to spread to other cells. To achieve the latter, influenza uses another glycoprotein, the enzyme neuraminidase (NA), to cleave the sialic acid receptors from the surface of the original host cell. This paper traces the development of anti-influenza drugs, from the initial suggestion by MacFarlane Burnet in 1948 that an effective 'competitive poison' of the virus' NA might be useful in controlling infection by the virus, through to the determination of the structure of NA by X-ray crystallography and the realization of Burnet's idea with the design of NA inhibitors. A focus is the contribution of the late William Graeme Laver, FRS, to this research.
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Affiliation(s)
- Elspeth F Garman
- Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
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7
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Buschiazzo A, Muiá R, Larrieux N, Pitcovsky T, Mucci J, Campetella O. Trypanosoma cruzi trans-sialidase in complex with a neutralizing antibody: structure/function studies towards the rational design of inhibitors. PLoS Pathog 2012; 8:e1002474. [PMID: 22241998 PMCID: PMC3252381 DOI: 10.1371/journal.ppat.1002474] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 11/21/2011] [Indexed: 12/27/2022] Open
Abstract
Trans-sialidase (TS), a virulence factor from Trypanosoma cruzi, is an enzyme playing key roles in the biology of this protozoan parasite. Absent from the mammalian host, it constitutes a potential target for the development of novel chemotherapeutic drugs, an urgent need to combat Chagas' disease. TS is involved in host cell invasion and parasite survival in the bloodstream. However, TS is also actively shed by the parasite to the bloodstream, inducing systemic effects readily detected during the acute phase of the disease, in particular, hematological alterations and triggering of immune cells apoptosis, until specific neutralizing antibodies are elicited. These antibodies constitute the only known submicromolar inhibitor of TS's catalytic activity. We now report the identification and detailed characterization of a neutralizing mouse monoclonal antibody (mAb 13G9), recognizing T. cruzi TS with high specificity and subnanomolar affinity. This mAb displays undetectable association with the T. cruzi superfamily of TS-like proteins or yet with the TS-related enzymes from Trypanosoma brucei or Trypanosoma rangeli. In immunofluorescence assays, mAb 13G9 labeled 100% of the parasites from the infective trypomastigote stage. This mAb also reduces parasite invasion of cultured cells and strongly inhibits parasite surface sialylation. The crystal structure of the mAb 13G9 antigen-binding fragment in complex with the globular region of T. cruzi TS was determined, revealing detailed molecular insights of the inhibition mechanism. Not occluding the enzyme's catalytic site, the antibody performs a subtle action by inhibiting the movement of an assisting tyrosine (Y119), whose mobility is known to play a key role in the trans-glycosidase mechanism. As an example of enzymatic inhibition involving non-catalytic residues that occupy sites distal from the substrate-binding pocket, this first near atomic characterization of a high affinity inhibitory molecule for TS provides a rational framework for novel strategies in the design of chemotherapeutic compounds. Chagas' disease, or American trypanosomiasis, is an endemic illness that affects approximately 8 million people in Latin America. The etiologic agent is the protozoan parasite Trypanosoma cruzi. To survive in the mammalian host and invade its cells, leading to the chronic infection, the parasite incorporates a charged carbohydrate (sialic acid). However, the parasite is unable to synthesize sialic acid, having to scavenge it from the host's sialo-glycoconjugates, through a transglycosylation reaction catalyzed by the enzyme trans-sialidase, which is unique to these organisms. We have obtained a monoclonal antibody that fully inhibits T. cruzi trans-sialidase actually being, at the best of our knowledge, the most potent inhibitor available. We now report a complete characterization of this neutralizing monoclonal antibody, at the functional and molecular levels. The antibody displays very high affinity and specificity for the T. cruzi enzyme, labels the parasites' surface and effectively blocks its sialylation and host cell invasion capacities. The determination of the 3D structure of the enzyme-antibody immunocomplex by X ray diffraction, allowed us to unveil the inhibition mechanism, providing clues for rational drug design. Given that sialidases are virulence factors in several pathogenic microorganisms, the reported data shall help to expand informative knowledge in this area.
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MESH Headings
- Animals
- Antibodies, Monoclonal, Murine-Derived/chemistry
- Antibodies, Monoclonal, Murine-Derived/immunology
- Antibodies, Monoclonal, Murine-Derived/therapeutic use
- Antibodies, Neutralizing/chemistry
- Antibodies, Neutralizing/immunology
- Antibodies, Neutralizing/therapeutic use
- Binding Sites
- Chagas Disease/drug therapy
- Chagas Disease/enzymology
- Glycoproteins/antagonists & inhibitors
- Glycoproteins/chemistry
- Glycoproteins/immunology
- Mice
- Neuraminidase/antagonists & inhibitors
- Neuraminidase/chemistry
- Neuraminidase/immunology
- Protein Structure, Quaternary
- Trypanosoma cruzi/enzymology
- Trypanosoma cruzi/immunology
- Trypanosoma cruzi/pathogenicity
- Virulence Factors/antagonists & inhibitors
- Virulence Factors/chemistry
- Virulence Factors/immunology
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Affiliation(s)
- Alejandro Buschiazzo
- Institut Pasteur de Montevideo, Unit of Protein Crystallography, Montevideo, Uruguay
- Institut Pasteur, Department of Structural Biology and Chemistry, Paris, France
- * E-mail: (AB); (OC)
| | - Romina Muiá
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
| | - Nicole Larrieux
- Institut Pasteur de Montevideo, Unit of Protein Crystallography, Montevideo, Uruguay
| | - Tamara Pitcovsky
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
| | - Juan Mucci
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Oscar Campetella
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
- * E-mail: (AB); (OC)
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H5N1 virus-like particle vaccine elicits cross-reactive neutralizing antibodies that preferentially bind to the oligomeric form of influenza virus hemagglutinin in humans. J Virol 2011; 85:10945-54. [PMID: 21865396 DOI: 10.1128/jvi.05406-11] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Transmission of pathogenic avian influenza viruses (AIV) from wild birds to domestic poultry and humans is continuing in multiple countries around the world. In preparation for a potential AIV pandemic, multiple vaccine candidates are under development. In the case of H5N1 AIV, a clear shift in transmission from clade 1 to clade 2 viruses occurred in recent years. The virus-like particle (VLP) represents an economical approach to pandemic vaccine development. In the current study, we evaluated the humoral immune response in humans vaccinated with H5N1 A/Indonesia/05/2005 (clade 2.1) VLP vaccine manufactured in Sf9 insect cells. The VLPs were comprised of the influenza virus hemagglutinin (HA), neuraminidase (NA), and matrix 1 (M1) proteins. In an FDA-approved phase I/II human clinical study, two doses of H5N1 VLPs at 15, 45, or 90 μg HA/dose resulted in seroconversion and production of functional antibodies. Moreover, cross-reactivity against other clade 2 subtypes was demonstrated using virus neutralization assays. H5N1 whole-genome fragment phage display libraries (GFPDL) were used to elucidate the antibody epitope repertoire in postvaccination human sera. Diverse epitopes in HA1/HA2 and NA were recognized by postvaccination sera from the two high-dose groups, including large segments spanning the HA1 receptor binding domain. Importantly, the vaccine elicited sera that preferentially bound to an oligomeric form of recombinant HA1 compared with monomeric HA1. The oligomeric/monomeric HA1 binding ratios of the sera correlated with the virus neutralizing titers. Additionally, the two high-dose VLP vaccine groups generated NA-inhibiting antibodies that were associated with binding to a C-terminal epitope close to the sialic acid binding site. These findings represent the first report describing the quality of the antibody responses in humans following AIV VLP immunization and support further development of such vaccines against emerging influenza virus strains.
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9
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Affiliation(s)
- Peter M. Colman
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia 3050;
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10
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Mapping the sequence mutations of the 2009 H1N1 influenza A virus neuraminidase relative to drug and antibody binding sites. Biol Direct 2009; 4:18; discussion 18. [PMID: 19457254 PMCID: PMC2691737 DOI: 10.1186/1745-6150-4-18] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Accepted: 05/20/2009] [Indexed: 11/30/2022] Open
Abstract
In this work, we study the consequences of sequence variations of the "2009 H1N1" (swine or Mexican flu) influenza A virus strain neuraminidase for drug treatment and vaccination. We find that it is phylogenetically more closely related to European H1N1 swine flu and H5N1 avian flu rather than to the H1N1 counterparts in the Americas. Homology-based 3D structure modeling reveals that the novel mutations are preferentially located at the protein surface and do not interfere with the active site. The latter is the binding cavity for 3 currently used neuraminidase inhibitors: oseltamivir (Tamiflu®), zanamivir (Relenza®) and peramivir; thus, the drugs should remain effective for treatment. However, the antigenic regions of the neuraminidase relevant for vaccine development, serological typing and passive antibody treatment can differ from those of previous strains and already vary among patients. This article was reviewed by Sandor Pongor and L. Aravind.
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11
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12
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Moreau V, Fleury C, Piquer D, Nguyen C, Novali N, Villard S, Laune D, Granier C, Molina F. PEPOP: computational design of immunogenic peptides. BMC Bioinformatics 2008; 9:71. [PMID: 18234071 PMCID: PMC2262870 DOI: 10.1186/1471-2105-9-71] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Accepted: 01/30/2008] [Indexed: 11/10/2022] Open
Abstract
Background Most methods available to predict protein epitopes are sequence based. There is a need for methods using 3D information for prediction of discontinuous epitopes and derived immunogenic peptides. Results PEPOP uses the 3D coordinates of a protein both to predict clusters of surface accessible segments that might correspond to epitopes and to design peptides to be used to raise antibodies that target the cognate antigen at specific sites. To verify the ability of PEPOP to identify epitopes, 13 crystallographically defined epitopes were compared with PEPOP clusters: specificity ranged from 0.75 to 1.00, sensitivity from 0.33 to 1.00, and the positive predictive value from 0.19 to 0.89. Comparison of these results with those obtained with two other prediction algorithms showed comparable specificity and slightly better sensitivity and PPV. To prove the capacity of PEPOP to predict immunogenic peptides that induce protein cross-reactive antibodies, several peptides were designed from the 3D structure of model antigens (IA-2, TPO, and IL8) and chemically synthesized. The reactivity of the resulting anti-peptides antibodies with the cognate antigens was measured. In 80% of the cases (four out of five peptides), the flanking protein sequence process (sequence-based) of PEPOP successfully proposed peptides that elicited antibodies cross-reacting with the parent proteins. Polyclonal antibodies raised against peptides designed from amino acids which are spatially close in the protein, but separated in the sequence, could also be obtained, although they were much less reactive. The capacity of PEPOP to design immunogenic peptides that induce antibodies suitable for a sandwich capture assay was also demonstrated. Conclusion PEPOP has the potential to guide experimentalists that want to localize an epitope or design immunogenic peptides for raising antibodies which target proteins at specific sites. More successful predictions of immunogenic peptides were obtained when a peptide was continuous as compared with peptides corresponding to discontinuous epitopes. PEPOP is available for use at .
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Affiliation(s)
- Violaine Moreau
- CNRS FRE 3009, SysDiag, CAP DELTA, 1682 Rue de la Valsière, CS 61003, 34184 Montpellier Cedex 4, France.
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13
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Piekarska B, Drozd A, Konieczny L, Król M, Jurkowski W, Roterman I, Spólnik P, Stopa B, Rybarska J. The indirect generation of long-distance structural changes in antibodies upon their binding to antigen. Chem Biol Drug Des 2007; 68:276-83. [PMID: 17177888 DOI: 10.1111/j.1747-0285.2006.00448.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
An allosteric mechanism for the generation of long-distance structural alterations in Fab fragments of antibodies in immune complexes has been postulated and tested in theoretical and experimental analysis. The flexing and/or torsion-derived forces exerted on the elbow region in Fab arms of bivalent antibodies upon binding to antigen were assumed to drive the disruption of hydrogen bonds which stabilize N- and C-terminal chain fragments in V-domains. This allows an extra movement in the elbow followed by a relaxation in the Fab arm and may generate long-distance effects if, in particular, the structural changes are generated asymmetrically involving one chain of the Fab arm only. This mechanism was studied by simulation of molecular dynamics. The local instability in the area involving the site of packing of the N-terminal chain fragment allows penetration and binding of the supramolecular dye Congo red that hence becomes an indicator of the initiated relaxation process and is also the prospective ligand in studies of designing drugs. The susceptibility to dye binding was observed in complexation of bivalent antibodies only, supplying the evidence that constraints associating the interaction with randomly distributed antigenic determinants drive the local structural changes in the V-domain followed by long-distance effects.
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Affiliation(s)
- Barbara Piekarska
- Chair of Medical Biochemistry, Jagiellonian University Medical College, Kopernika 7, 31-034 Kraków, Poland.
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14
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Li Y, Parry G, Chen L, Callahan JA, Shaw DE, Meehan EJ, Mazar AP, Huang M. An anti-urokinase plasminogen activator receptor (uPAR) antibody: crystal structure and binding epitope. J Mol Biol 2006; 365:1117-29. [PMID: 17101149 DOI: 10.1016/j.jmb.2006.10.059] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2006] [Revised: 10/11/2006] [Accepted: 10/18/2006] [Indexed: 01/09/2023]
Abstract
Human urokinase-type plasminogen activator receptor (uPAR/CD87) is expressed at the invasive interface of the tumor-stromal microenvironment in many human cancers and interacts with a wide array of extracellular molecules. An anti-uPAR antibody (ATN615) was prepared using hybridoma technology. This antibody binds to uPAR in vitro with high affinity (K(d) approximately 1 nM) and does not interfere with uPA binding to uPAR. Here we report the crystal structure of the Fab fragment of ATN615 at 1.77 A and the analysis of ATN615-suPAR-ATF structure that was previously determined, emphasizing the ATN615-suPAR interaction. The complementarity determining regions (CDRs) of ATN615 consist of a high percentage of aromatic residues, and form a relatively flat and undulating surface. The ATN615 Fab fragment recognizes domain 3 of suPAR. The antibody-antigen recognition involves 11 suPAR residues and 12 Fab residues from five CDRs. Structural data suggest that Pro188, Asn190, Gly191, and Arg192 residues of uPAR are the key residues for the antibody recognition, while Pro189 and Arg192 render specificity of ATN615 for human uPAR. Interestingly, this antibody-antigen interface has a small contact area, mainly polar interaction with little hydrophobic character, yet has high binding strength. Furthermore, several solvent molecules (assigned as polyethylene glycols) were clearly visible in the binding interface between antibody and antigen, suggesting that solvent molecules may be important for the maximal binding between suPAR and ATN615 Fab. ATN615 undergoes small but noticeable changes in its CDR region upon antigen binding.
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Affiliation(s)
- Yongdong Li
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, 155 Yang Qiao Xi Lu, Fuzhou 350002, People's Republic of China
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15
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Longo NS, Lipsky PE. Why do B cells mutate their immunoglobulin receptors? Trends Immunol 2006; 27:374-80. [PMID: 16809065 DOI: 10.1016/j.it.2006.06.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Revised: 05/18/2006] [Accepted: 06/14/2006] [Indexed: 01/12/2023]
Abstract
B cells have the unique ability to acquire large numbers of point mutations in the variable segment of rearranged immunoglobulin (Ig) genes during a germinal center reaction. It is broadly accepted that somatic hypermutation (SHM) and affinity maturation are required to generate memory B cells and to produce antibodies capable of accomplishing the host defense functions of the humoral component of the adaptive immune system. However, several studies illustrate that low-avidity interactions between antigen and the B-cell receptor can induce deletion, receptor editing and a T-dependent immune response, suggesting that the high-avidity binding of antigen is not essential. If enhanced antigen binding is not essential for immune responses, what is the purpose of SHM? An alternative benefit of SHM might be to enhance the ability of B cells to track antigens expressed by rapidly mutating microorganisms.
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Affiliation(s)
- Nancy S Longo
- Repertoire Analysis Group, Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases/ NIH, Bethesda, MD 20892-1560, USA
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16
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Król M, Roterman I, Piekarska B, Konieczny L, Rybarska J, Stopa B. Local and long-range structural effects caused by the removal of the N-terminal polypeptide fragment from immunoglobulin L chain lambda. Biopolymers 2003; 69:189-200. [PMID: 12767122 DOI: 10.1002/bip.10355] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The role of the N-terminal polypeptide fragment of the immunoglobulin l-chain in V domain packing stability, and the flexibility of the whole chain was approached by molecular dynamics simulation. The observations were supported by experimental analysis. The N-terminal polypeptide fragment appeared to be the low-stability packing element in the V domain. At moderately elevated temperature it may be replaced at its packing locus by Congo red and then removed by proteolysis. After removal of Congo red by adsorption to (diethylamino)ethyl (DEAE) cellulose, the stability of complete L chain and of L chain devoid of the N-terminal polypeptide fragment were compared. The results indicated that the N-terminal polypeptide fragment plays an essential role in the stability of the V domain. Its removal makes the domain accessible for ANS and Congo red dye binding without heating. The decreased domain stability was registered in particular as increased root mean square (RMS) fluctuation and higher susceptibility to proteolytic attack. The long-range effect was most clearly manifested at 340 K as independent V and C domain fluctuation in the l-chain devoid of the N-terminal polypeptide fragment. This is likely due to the lack of direct connections between the N- and C-termini of the V domain polypeptide. In a complete V domain the connection involves residues 8-12 and 106-110 in particular. Partial or complete disruption of this connection increases the freedom of V domain rotation, while its increased cohesion strengthens the coupling of the V and C domains, making the whole L chain less flexible.
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Affiliation(s)
- Marcin Król
- Department of Biostatistics and Medical Informatics, Collegium Medicum, Jagiellonian University, 17 Kopernika St, Kraków, 31-501 Poland
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17
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Gulati U, Hwang CC, Venkatramani L, Gulati S, Stray SJ, Lee JT, Laver WG, Bochkarev A, Zlotnick A, Air GM. Antibody epitopes on the neuraminidase of a recent H3N2 influenza virus (A/Memphis/31/98). J Virol 2002; 76:12274-80. [PMID: 12414967 PMCID: PMC136895 DOI: 10.1128/jvi.76.23.12274-12280.2002] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2002] [Accepted: 08/23/2002] [Indexed: 11/20/2022] Open
Abstract
We have characterized monoclonal antibodies raised against the neuraminidase (NA) of a Sydney-like influenza virus (A/Memphis/31/98, H3N2) in a reassortant virus A/NWS/33(HA)-A/Mem/31/98(NA) (H1N2) and nine escape mutants selected by these monoclonal antibodies. Five of the antibodies use the same heavy chain VDJ genes and may not be independent. Another antibody, Mem5, uses the same V(H) and J genes with a different D gene and different isotype. Sequence changes in escape mutants selected by these antibodies occur in two loops of the NA, at amino acid 198, 199, 220, or 221. These amino acids are located on the opposite side of the NA monomer to the major epitopes found in N9 and early N2 NAs. Escape mutants with a change at 198 have reduced NA activity compared to the wild-type virus. Asp198 points toward the substrate binding pocket, and we had previously found that a site-directed mutation of this amino acid resulted in a loss of enzyme activity (M. R. Lentz, R. G. Webster, and G. M. Air, Biochemistry 26:5351-5358, 1987). Mutations at residue 199, 220, or 221 did not alter the NA activity significantly compared to that of wild-type NA. A 3.5-A structure of Mem5 Fab complexed with the Mem/98 NA shows that the Mem5 antibody binds at the sites of escape mutation selected by the other antibodies.
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Affiliation(s)
- Upma Gulati
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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18
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Abstract
We are interested in studying how influenza virus escapes antibody inhibition. Based on the structure of the complex between N9 NA and monoclonal antibody NC10 Fab (R. L. Malby, W. R. Tulip, V. R. Harley, J. L. McKimm-Breschkin, W. G. Laver, R. G. Webster, and P. M. Colman, 1994, Structure 2, 733-746), we investigated the contribution made by individual amino acids to the stability of the complex. We made conservative changes in residues that are centrally located in the epitope and more drastic changes in peripheral contacts. The mutations made were N200L (removing an N-linked oligosaccharide), N329Q, N345Q, S370T, S372A, N400L, and K432M. Binding of each mutant to NC10 was quantitated by NA inhibition assays and ELISA. Except for N200L and N329Q, the mutants were inhibited by NC10 to the same extent as wild-type NA although with less affinity. The enzyme activity (K(cat)) of N200L is 80% reduced, indicating a defect in folding or assembly; therefore, the loss in binding activity due to the missing sugar residue cannot be assessed. The K(d) for N329Q is sixfold higher than for wild-type NA in the inhibition test, but the same as wild-type in ELISA, indicating a change in disposition of the antibody but no loss of affinity. The results show that the NC10 epitope can accommodate a change at any site and is not dominated by a few high-energy interactions as was found in the NC41 epitope. We propose that the difference lies in the contribution of buried water molecules to the NA-NC10 complex.
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Affiliation(s)
- Janis T Lee
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73190, USA
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19
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Epa VC, Colman PM. Shape and electrostatic complementarity at viral antigen-antibody complexes. Curr Top Microbiol Immunol 2001; 260:45-53. [PMID: 11443880 DOI: 10.1007/978-3-662-05783-4_3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Affiliation(s)
- V C Epa
- Biomolecular Research Institute, 343 Royal Parade, Parkville, Victoria 3052, Australia
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20
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Greenspan NS. Affinity, complementarity, cooperativity, and specificity in antibody recognition. Curr Top Microbiol Immunol 2001; 260:65-85. [PMID: 11443882 DOI: 10.1007/978-3-662-05783-4_5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Affiliation(s)
- N S Greenspan
- Institute of Pathology, Biomedical Research Building, Room 927, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-4943, USA
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21
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Abstract
Although recognition and specificity are among the most fundamental concepts in immunology, there is a common tendency to equate these notions with the fit, especially in terms of molecular shape, between interacting molecules. Even in the case of monovalent recognition, there are factors that contribute to the energetics of the interaction that are not readily accounted for by detailed structural analysis of the interacting (epitopic and paratopic) molecular surfaces. Consequently, recognition involves more than just the three spatial dimensions and time. Factors such as solute-solvent interactions, molecular crowding, and confinement, not directly related to the details of the intermolecular interface, can play crucial roles in determining both intrinsic affinity and differential intrinsic affinity. Furthermore, stating that a given structural subunit (e.g., amino acid) is recognized in a given noncovalent interaction does not clarify whether the structural subunit in question participates in the interaction through van der Waals contact, contribution to intrinsic affinity, or differential contribution to relative intrinsic affinities for two or more different ligands. Additional factors become relevant in considering the specificity exhibited in multivalent interactions, cell activation, and activation of the whole immune system. Therefore, specificity as defined for a monovalent binding event can diverge from specificity as it is defined for higher-order interactions. A corollary of this conclusion is that the composition of epitopes and paratopes, defined in terms of the structural elements for which substitutions have an effect on the specificity-defining measurement, can differ in different contexts despite complete conservation of the structures that physically make direct contact. An analysis of specificity at the organismal level suggests that the immune system does not recognize or respond to substances that correspond precisely to either nonself substances or to dangerous substances. An alternative notion for the molecular origins of immunological discrimination does not require that there be any single reason for immune responsiveness. This concept of what the immune system recognizes and responds to derives from the recognition that the ultimate function of the immune system is to contribute to survival and reproductive success through any available means.
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Affiliation(s)
- N S Greenspan
- Institute of Pathology, Case Western Reserve University, Cleveland, Ohio 44106, USA
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22
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Fleury D, Daniels RS, Skehel JJ, Knossow M, Bizebard T. Structural evidence for recognition of a single epitope by two distinct antibodies. Proteins 2000. [DOI: 10.1002/1097-0134(20000901)40:4<572::aid-prot30>3.0.co;2-n] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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23
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Vaughan CK, Buckle AM, Fersht AR. Structural response to mutation at a protein-protein interface. J Mol Biol 1999; 286:1487-506. [PMID: 10064711 DOI: 10.1006/jmbi.1998.2559] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have crystallised three mutants of the barnase-barstar complex in which interactions across the interface have been deleted by simultaneous mutation of both residues involved in the interaction. Each mutant deletes a different type of interaction at the interface: the first complex bnHis102-->Ala-bsTyr29-->Phe (bn, barnase; bs, barstar), deletes a van der Waals packing interaction; the second complex, bnLys27-->Ala-bsThr42-->Ala, deletes a hydrogen bond; the third, bnLys27-->Ala-bsAsp35-->Ala, deletes a long-range charge-charge interaction. The contribution of each of these side-chains to the stability of the complex is known; the coupling energy between the deleted side-chains is also known. Despite each of the double mutants being significantly destabilised compared with the wild-type, the effects of mutation are local. Only small movements in the main-chain surrounding the sites of mutation and some larger movements of neighbouring side-chains are observed in the mutant complexes. The exact response to mutation is context-dependent and for the same mutant can vary depending upon the environment within the crystal. In some double mutant complexes, interfacial pockets, which are accessible to bulk solvent are formed, whereas interfacial cavities which are isolated from bulk solvent, are formed in others. In all double mutants, water molecules fill the created pockets and cavities. These water molecules mimic the deleted side-chains by occupying positions close to the non-carbon atoms of truncated side-chains and re-making many hydrogen bonds made by the truncated side-chains in the wild-type. It remains extremely difficult, however, to correlate energetic and structural responses to mutation because of unknown changes in entropy and entropy-enthalpy compensation.
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Affiliation(s)
- C K Vaughan
- MRC Centre for Protein Engineering, Hills Road, Cambridge, CB2 2QH, UK
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24
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Fan ZC, Shan L, Goldsteen BZ, Guddat LW, Thakur A, Landolfi NF, Co MS, Vasquez M, Queen C, Ramsland PA, Edmundson AB. Comparison of the three-dimensional structures of a humanized and a chimeric Fab of an anti-gamma-interferon antibody. J Mol Recognit 1999; 12:19-32. [PMID: 10398393 DOI: 10.1002/(sici)1099-1352(199901/02)12:1<19::aid-jmr445>3.0.co;2-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The objective of this work is to compare the three-dimensional structures of "humanized" and mouse-human chimeric forms of a murine monoclonal antibody elicited against human gamma-interferon. It is also to provide structural explanations for the small differences in the affinities and biological interactions of the two molecules for this antigen. Antigen-binding fragments (Fabs) were produced by papain hydrolysis of the antibodies and crystallized with polyethylene glycol (PEG) 8,000 by nearly identical microseeding procedures. Their structures were solved by X-ray analyses at 2.9 A resolution, using molecular replacement methods and crystallographic refinement. Comparison of these structures revealed marked similarities in the light (L) chains and near identities of the constant (C) domains of the heavy (H) chains. However, the variable (V) domains of the heavy chains exhibited substantial differences in the conformations of all three complementarity-determining regions (CDRs), and in their first framework segments (FR1). In FR1 of the humanized VH, the substitution of serine for proline in position 7 allowed the N-terminal segment (designated strand 4-1) to be closely juxtaposed to an adjacent strand (4-2) and form hydrogen bonds typical of an antiparallel beta-pleated sheet. The tightening of the humanized structure was relayed in such a way as to decrease the space available for the last portion of HFR1 and the first part of HCDR1. This compression led to the formation of an alpha-helix involving residues 25-32. With fewer steric constraints, the corresponding segment in the chimeric Fab lengthened by at least 1 A to a random coil which terminated in a single turn of 310 helix. In the humanized Fab, HCDR1, which is sandwiched between HCDR2 and HCDR3, significantly influenced the structures of both regions. HCDR2 was forced into a bent and twisted orientation different from that in the chimeric Fab, both at the crown of the loop (around proline H52a) and at its base. As in HCDR1, the last few residues of HCDR2 in the humanized Fab were compressed into a space-saving alpha-helix, contrasting with a more extended 310 helix in the chimeric form. HCDR3 in the humanized Fab was also adjusted in shape and topography. The observed similarities in the functional binding activities of the two molecules can be rationalized by limited induced fit adjustments in their structures on antigen binding. While not perfect replicas, the two structures are testimonials to the progress in making high affinity monoclonal antibodies safe for human use.
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Affiliation(s)
- Z C Fan
- Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK 73104, USA
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25
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Molecular dissection of protein antigens and the prediction of epitopes. SYNTHETIC PEPTIDES AS ANTIGENTS 1999. [DOI: 10.1016/s0075-7535(08)70446-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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26
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Mylvaganam SE, Paterson Y, Getzoff ED. Structural basis for the binding of an anti-cytochrome c antibody to its antigen: crystal structures of FabE8-cytochrome c complex to 1.8 A resolution and FabE8 to 2.26 A resolution. J Mol Biol 1998; 281:301-22. [PMID: 9698550 DOI: 10.1006/jmbi.1998.1942] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A complete understanding of antibody-antigen association and specificity requires the stereochemical description of both antigen and antibody before and upon complex formation. The structural mechanism involved in the binding of the IgG1 monoclonal antibody E8 to its highly charged protein antigen horse cytochrome c (cyt c) is revealed by crystallographic structures of the antigen-binding fragment (Fab) of E8 bound to cyt c (FabE8-cytc), determined to 1.8 A resolution, and of uncomplexed Fab E8 (FabE8), determined to 2.26 A resolution. E8 antibody binds to three major discontiguous segments (33 to 39; 56 to 66; 96 to 104), and two minor sites on cyt c opposite to the exposed haem edge. Crystallographic definition of the E8 epitope complements and extends biochemical mapping and two-dimensional nuclear magnetic resonance with hydrogen-deuterium exchange studies. These combined results demonstrate that antibody-induced stabilization of secondary structural elements within the antigen can propagate locally to adjacent residues outside the epitope. Pre-existing shape complementarity at the FabE8-cytc interface is enhanced by 48 bound water molecules, and by local movements of up to 4.2 A for E8 antibody and 8.9 A for cyt c. Glu62, Asn103 and the C-terminal Glu104 of cyt c adjust to fit the pre-formed VL "hill" and VH "valley" shape of the grooved E8 paratope. All six E8 complementarity determining regions (CDRs) contact the antigen, with CDR L1 forming 46% of the total atomic contacts, and CDRs L1 (29%) and H3 (20%) contributing the highest percentage of the total surface area of E8 buried by cyt c (550 A2). The E8 antibody covers 534 A2 of the cyt c surface. The formation of five ion pairs between E8 and flexible cyt c residues Lys60, Glu62 and Glu104 suggests the importance of mobile regions and electrostatic interactions in providing the exquisite specificity needed for recognition of this extremely conserved protein antigen. The highly homologous VL domains of E8 and anti-lysozyme antibody D1. 3 achieve their distinct antigen-binding specificities by expanding the impact of their limited sequence differences through the recruitment of different sets of conserved residues and distinctly different CDR L3 conformations.
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Affiliation(s)
- S E Mylvaganam
- Department of Molecular Biology and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Rd, La Jolla, CA 92037, USA.
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27
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Vallone B, Miele AE, Vecchini P, Chiancone E, Brunori M. Free energy of burying hydrophobic residues in the interface between protein subunits. Proc Natl Acad Sci U S A 1998; 95:6103-7. [PMID: 9600924 PMCID: PMC27592 DOI: 10.1073/pnas.95.11.6103] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/1998] [Accepted: 03/05/1998] [Indexed: 02/07/2023] Open
Abstract
We have obtained an experimental estimate of the free energy change associated with variations at the interface between protein subunits, a subject that has raised considerable interest since the concept of accessible surface area was introduced by Lee and Richards [Lee, B. & Richards, F. M. (1971) J. Mol. Biol. 55, 379-400]. We determined by analytical ultracentrifugation the dimer-tetramer equilibrium constant of five single and three double mutants of human Hb. One mutation is at the stationary alpha1 beta1 interface, and all of the others are at the sliding alpha1 beta2 interface where cleavage of the tetramer into dimers and ligand-linked allosteric changes are known to occur. A surprisingly good linear correlation between the change in the free energy of association of the mutants and the change in buried hydrophobic surface area was obtained, after corrections for the energetic cost of losing steric complementarity at the alphabeta dimer interface. The slope yields an interface stabilization free energy of -15 +/- 1.2 cal/mol upon burial of 1 A2 of hydrophobic surface, in very good agreement with the theoretical estimate given by Eisenberg and McLachlan [Eisenberg, D. & McLachlan, A. D. (1986) Nature (London) 319, 199-203].
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Affiliation(s)
- B Vallone
- Istituto Pasteur-Fondazione Cenci Bolognetti e Centro di Biologia Molecolare del Consiglio Nazionale delle Ricerche, c/o Dipartimento di Scienze Biochimiche, Università di Roma "La Sapienza," P.le A. Moro 5, 00185 Rome, Italy
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28
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Andersson K, Wrammert J, Leanderson T. Affinity selection and repertoire shift: paradoxes as a consequence of somatic mutation? Immunol Rev 1998; 162:173-82. [PMID: 9602363 DOI: 10.1111/j.1600-065x.1998.tb01440.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Affinity selection of antibodies during immune responses relies on two mechanisms, one molecular that involves the targeted introduction of somatic mutations into rearranged immunoglobulin genes and one cellular that involves the clonal expansion of B cells expressing a surface immunoglobulin with a higher affinity for antigen compared to their competitors. In this review we focus on the conditions for affinity selection during the establishment, expansion and memory phases of the immune response. We postulate that somatic mutation evolved prior to affinity selection and we present a model for selection of B cells in germinal centres. We also discuss the possibility that antibody repertoire shift occurs during the memory maintenance phase. Finally, we argue that a significant affinity selection and a selection for polyclonality of immune responses occur during this stage of the immune response.
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Affiliation(s)
- K Andersson
- Department of Cellular and Molecular Biology, Lund University, Sweden
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29
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Huang M, Syed R, Stura EA, Stone MJ, Stefanko RS, Ruf W, Edgington TS, Wilson IA. The mechanism of an inhibitory antibody on TF-initiated blood coagulation revealed by the crystal structures of human tissue factor, Fab 5G9 and TF.G9 complex. J Mol Biol 1998; 275:873-94. [PMID: 9480775 DOI: 10.1006/jmbi.1997.1512] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The tissue factor (TF)-initiated blood coagulation protease cascade can be greatly inhibited in vivo by a potent anti-human-TF monoclonal antibody, 5G9. This antibody binds the carboxyl module of the extracellular domain of TF with a nanomolar binding constant and inhibits the formation of the TF.VIIa.X ternary initiation complex. We have determined the crystal structures of the extra-cellular modules of human TF, Fab 5G9, and their complex (TF.5G9) to 2.4 A, 2. 5 A, and 3.0 A, respectively, and measured the apparent inhibition constants of 5G9 on a panel of TF mutants. In our unliganded TF structure, a 7 degrees change in the relative orientation between the D1 and D2 modules was observed when compared with other published TF structures. Comparison of the free and bound Fab 5G9 indicates that small segmental and side chain variation of the antibody complementarity determining regions occurred on complexation with TF. The antibody-antigen recognition involves 18 TF antigen residues and 19 Fab residues from six CDR with one of the largest buried surface areas seen to date. A combination of structural and mutagenesis data indicate that Tyr156, Lys169, Arg200, and Lys201 play the major role in the antibody recognition. The TF. 5G9 structure provides insights into the mechanism by which the antibody 5G9 inhibits formation of the TF.VIIa.X ternary complex.
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Affiliation(s)
- M Huang
- Department of Molecular Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92027, USA
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30
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Gibas CJ, Subramaniam S, McCammon JA, Braden BC, Poljak RJ. pH dependence of antibody/lysozyme complexation. Biochemistry 1997; 36:15599-614. [PMID: 9398288 DOI: 10.1021/bi9701989] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Association between proteins often depends on the pH and ionic strength conditions of the medium in which it takes place. This is especially true in complexation involving titratable residues at the complex interface. Continuum electrostatics methods were used to calculate the pH-dependent energetics of association of hen egg lysozyme with two closely related monoclonal antibodies raised against it and the association of these antibodies against an avian species variant. A detailed analysis of the energetic contributions reveals that even though the hallmark of association in the two complexes is the presence of conserved charged-residue interactions, the environment of these interactions significantly influences the titration behavior and concomitantly the energetics. The contributing factors include minor structural rearrangements, buried interfacial area, dielectric environment of the key titratable residues, and geometry of the residue dispositions. Modeled structures of several mutant complexes were also studied so as to further delineate the contribution of individual factors to the titration behavior.
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Affiliation(s)
- C J Gibas
- Department of Molecular and Integrative Physiology, Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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31
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Shick KA, Xavier KA, Rajpal A, Smith-Gill SJ, Willson RC. Association of the anti-hen egg lysozyme antibody HyHEL-5 with avian species variant and mutant lysozymes. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1340:205-14. [PMID: 9252107 DOI: 10.1016/s0167-4838(97)00035-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The energetics of association of the murine anti-hen egg lysozyme antibody HyHEL-5 with bobwhite quail lysozyme, California quail lysozyme, and the Arg45-->Lys mutant of hen egg lysozyme was characterized by isothermal titration calorimetry. The association of each lysozyme with HyHEL-5 is enthalpically driven in the temperature range 10 degrees C to 37 degrees C. The calorimetric results indicate that the salt-links between Arg45 and Arg68 of hen egg lysozyme and GluH50 on the HyHEL-5 paratope are energetically important in HyHEL-5/HEL association. In contrast to previous studies, the results suggest that the three characteristic 'quail' mutations affect the energetics of antibody/antigen association, even though they are buried and not in direct contact with the antibody.
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Affiliation(s)
- K A Shick
- Department of Chemical Engineering, University of Houston, TX 77204-4792, USA
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32
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Abstract
Variation in the proteins produced by animal viruses allows the virus to reinfect the same host, but is constrained by the requirement to maintain critical viral functions, in particular engagement with cellular receptors. The fundamental characteristics of proteins and their interactions with each other suggest that this may not be so much of a constraint at all.
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Affiliation(s)
- P M Colman
- Biomolecular Research Institute, 343 Royal Parade, Parkville, Victoria 3052, Australia.
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33
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Smith KD, Kurago ZB, Lutz CT. Conformational changes in MHC class I molecules. Antibody, T-cell receptor, and NK cell recognition in an HLA-B7 model system. Immunol Res 1997; 16:243-59. [PMID: 9379075 DOI: 10.1007/bf02786393] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In this article we review the role of MHC conformation, including peptide-induced MHC conformation, in forming antibody (Ab), T-cell receptor (TCR), and natural killer (NK) cell receptor epitopes. Abs recognize conformational major histocompatibility (MHC) epitopes that often are influenced by the identity of MHC-bound peptide. Diverse TCRs recognize a common docking site on peptide/MHC complexes and directly contact peptide. Human NK cell inhibitory receptors (KIR) appear to recognize limited regions of the HLA alpha (1) helix. DX9+ KIR specifically focus on HLA-B residues 82 and 83. However, NK cells recognize much broader regions of HLA class I molecules and are sensitive to bound peptides. Thus, several classes of lymphocyte receptors are peptide-specific. Peptide specificity could be the result of direct contact with the receptor, or to conformational shifts in MHC residues that interact with both receptor and bound peptide.
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Affiliation(s)
- K D Smith
- Department of Pathology, University of Iowa College of Medicine, Iowa City 52242-1182, USA
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34
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Li YY, Smith KD, Shi Y, Lutz CT. Alloreactive anti-HLA-B7 cytolytic T cell clones use restricted T cell receptor genes. Transplantation 1996; 62:954-61. [PMID: 8878390 DOI: 10.1097/00007890-199610150-00014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Most alloreactive T cells specifically recognize peptides bound to donor MHC molecules. In addition to peptides, solvent accessible MHC residues also may stimulate alloreactive T cells. We studied T cell receptor (TCR) usage by 16 independent anti-HLA-B7 alloreactive cytolytic T lymphocyte (CTL) clones. Most or all of these CTL clones recognized unique peptides bound to HLA-B7. Despite the diversity of peptides recognized, 11 out of 15 CTL clones analyzed expressed TCR V(alpha) gene segment (AV) subgroups 1 and 3. Within AV subgroup 1, four of six clones expressed AV2; within AV subgroup 3, three clones used AV6. Ten of 14 CTL clones analyzed expressed V(beta) gene segment (BV) subgroups 4 and 1. In subgroup 4, BV14 was expressed by four of five alloreactive CTL clones. Similar AV and BV usage restriction was not found in mitogen-stimulated peripheral blood T cells from the major donor of the CTL clones. TCR A and TCR B junctional region sequences were quite diverse in length and sequence, although two CTL clones expressed nearly identical TCR B chains. We found no correlation between TCR AV or TCR BV usage and CTL recognition of 81 HLA-B7 variants. These results are consistent with models of TCR structure, in which very diverse TCR CDR3 regions contact very diverse peptides, and moderately diverse TCR CDR1 and CDR2 regions contact moderately diverse MHC alpha-helices.
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Affiliation(s)
- Y Y Li
- Department of Pathology, University of Iowa College of Medicine, Iowa City 52242, USA
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35
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Chacko S, Silverton EW, Smith-Gill SJ, Davies DR, Shick KA, Xavier KA, Willson RC, Jeffrey PD, Chang CY, Sieker LC, Sheriff S. Refined structures of bobwhite quail lysozyme uncomplexed and complexed with the HyHEL-5 Fab fragment. Proteins 1996; 26:55-65. [PMID: 8880929 DOI: 10.1002/(sici)1097-0134(199609)26:1<55::aid-prot5>3.0.co;2-f] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The HyHEL-5 antibody has more than a thousandfold lower affinity for bobwhite quail lysozyme (BWQL) than for hen egg-white lysozyme (HEL). Four sequence differences exist between BWQL and HEL, of which only one is involved in the interface with the Fab. The structure of bobwhite quail lysozyme has been determined in the uncomplexed state in two different crystal forms and in the complexed state with HyHEL-5, an antihen egg-white lysozyme Fab. Similar backbone conformations are observed in the three molecules of the two crystal forms of uncomplexed BWQL, although they show considerable variability in side-chain conformation. A relatively mobile segment in uncomplexed BWQL is observed to be part of the HyHEL-5 epitope. No major backbone conformational differences are observed in the lysozyme upon complex formation, but side-chain conformational differences are seen in surface residues that are involved in the interface with the antibody. The hydrogen bonding in the interface between BWQL and HyHEL-5 is similar to that in previously determined lysozyme-HyHEL-5 complexes.
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Affiliation(s)
- S Chacko
- Laboratory of Molecular Biology, NIDDK, NIH, Bethesda, Maryland 20895, USA
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36
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Abstract
There are now several crystal structures of antibody Fab fragments complexed to their protein antigens. These include Fab complexes with lysozyme, two Fab complexes with influenza virus neuraminidase, and three Fab complexes with their anti-idiotype Fabs. The pattern of binding that emerges is similar to that found with other protein-protein interactions, with good shape complementarity between the interacting surfaces and reasonable juxtapositions of polar residues so as to permit hydrogen-bond formation. Water molecules have been observed in cavities within the interface and on the periphery, where they often form bridging hydrogen bonds between antibody and antigen. For the most part the antigen is bound in the middle of the antibody combining site with most of the six complementarity-determining residues involved in binding. For the most studied antigen, lysozyme, the epitopes for four antibodies occupy approximately 45% of the accessible surface area. Some conformational changes have been observed to accompany binding in both the antibody and the antigen, although most of the information on conformational change in the latter comes from studies of complexes with small antigens.
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Affiliation(s)
- D R Davies
- Laboratory of Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0560, USA
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37
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Affiliation(s)
- E A Padlan
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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38
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Lea S, Abu-Ghazaleh R, Blakemore W, Curry S, Fry E, Jackson T, King A, Logan D, Newman J, Stuart D. Structural comparison of two strains of foot-and-mouth disease virus subtype O1 and a laboratory antigenic variant, G67. Structure 1995; 3:571-80. [PMID: 8590018 DOI: 10.1016/s0969-2126(01)00191-5] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Foot-and-mouth disease viruses (FMDVs) are members of the picornavirus family and cause an economically important disease of cloven-hoofed animals. To understand the structural basis of antigenic variation in FMDV, we have determined the structures of two viruses closely related to strain O1BFS whose structure is known. RESULTS The two new structure are, like O1BFS, both serotype O viruses. The first, O1 Kaüfbeuren (O1K), is a field isolate dating from an outbreak of FMD in Europe in the 1960s. The second, called G67, is a quadruple mutant of O1K, generated in the laboratory, that bears point mutations conferring resistance to neutralizing by monoclonal antibodies, specific for each of the four major antigenic sites defined previously. The availability of the three related virus structures permits a detailed analysis of the way amino acid substitutions influence antigenicity. Structural changes are seen to be limited, in general, to the substituted side chain. For example, the GH loop of VP1, a highly antigenic and mobile protuberance which becomes ordered only under reducing conditions, was essentially indistinguishable in the three viruses despite the accumulation of up to four changes within its 15-residue sequence. At one of the other antigenic sites, however, changes between the two field strains did perturb both side-chain and main-chain structures in the vicinity. CONCLUSIONS The conservation of conformation of the GH loop of VP1 adds to the evidence implicating an integrin as the cellular receptor for FMDV, since this loop contains a conserved RGD (Arg-Gly-Asp) sequence structurally similar to the same tripeptide in some other integrin-binding proteins. Structural changes required for the virus to escape neutralization by monoclonal antibodies are generally small. The more extensive type of structural change exhibited by the field isolates probably reflects differing selective pressures operating in vivo and in vitro.
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Affiliation(s)
- S Lea
- Oxford Centre for Molecular Sciences, New Chemistry Laboratory, UK
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39
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Abstract
Sites are microenvironments within a biomolecular structure, distinguished by their structural or functional role. A site can be defined by a three-dimensional location and a local neighborhood around this location in which the structure or function exists. We have developed a computer system to facilitate structural analysis (both qualitative and quantitative) of biomolecular sites. Our system automatically examines the spatial distributions of biophysical and biochemical properties, and reports those regions within a site where the distribution of these properties differs significantly from control nonsites. The properties range from simple atom-based characteristics such as charge to polypeptide-based characteristics such as type of secondary structure. Our analysis of sites uses non-sites as controls, providing a baseline for the quantitative assessment of the significance of the features that are uncovered. In this paper, we use radial distributions of properties to study three well-known sites (the binding sites for calcium, the milieu of disulfide bridges, and the serine protease active site). We demonstrate that the system automatically finds many of the previously described features of these sites and augments these features with some new details. In some cases, we cannot confirm the statistical significance of previously reported features. Our results demonstrate that analysis of protein structure is sensitive to assumptions about background distributions, and that these distributions should be considered explicitly during structural analyses.
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Affiliation(s)
- S C Bagley
- Section on Medical Informatics, Stanford University School of Medicine, California 94305-5479, USA
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40
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Van Eyk JE, Caday-Malcolm RA, Yu L, Irvin RT, Hodges RS. Anti-peptide monoclonal antibody imaging of a common binding domain involved in muscle regulation. Protein Sci 1995; 4:781-90. [PMID: 7613476 PMCID: PMC2143110 DOI: 10.1002/pro.5560040418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Multiple-component regulatory protein systems function through a generalized mechanism where a single regulatory protein or ligand binds to a variety of receptors to modulate specific functions in a physiologically sensitive context. Muscle contraction is regulated by the interaction of actin with troponin I (TnI) or myosin in a Ca(2+)-sensitive manner. Actin utilizes a single binding domain (residues 1-28) to bind to residues 104-115 of TnI (Van Eyk JE, Sönnichsen FD, Sykes BD, Hodges RS, 1991, In: Rüegg JC, ed, Peptides as probes in muscle research, Heidelberg, Germany: Springer-Verlag, pp 15-31) and to myosin subfragment 1 (S1, an enzymatic fragment of myosin containing both the actin and ATP binding sites) (Van Eyk JE, Hodges RS, 1991, Biochemistry 30:11676-11682) in a Ca(2+)-sensitive manner. We have utilized an anti-TnI peptide (104-115) monoclonal antibody, Mab B4, that binds specifically to TnI, to image the common binding domain of actin and thus mimic the activity of actin including activation of the S1 ATPase activity and TnI-mediated regulation of the S1 ATPase. Mab B4 has also been utilized to identify a receptor binding domain on myosin (residues 633-644) that is recognized by actin. Interestingly, Mab B4 binds to the native protein receptors TnI and S1 with relative affinities of 100- and 25,000-fold higher than the binding affinity to the 12-residue peptide immunogen. Thus, anti-peptide monoclonal antibodies prepared against a receptor binding domain can mimic the ligand binding domain and be utilized as a powerful tool for the detailed analysis of complex multiple-component regulatory systems.
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Affiliation(s)
- J E Van Eyk
- Department of Biochemistry and Medical Research Council of Canada Group in Protein Structure and Function, University of Alberta, Edmonton, Canada
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41
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Abstract
A considerable part of important biological processes is governed by the noncovalent association of peptides and proteins. Various types of intermolecular forces may be involved in the formation of these molecular assemblies. This review gives a brief account of the physicochemical bases of interactive forces, with special emphasis on their impact on various peptide-protein interactions; summarizes the newest biochemical and biophysical methods for the study of such interactions; and discusses the role of various hydrophilic and hydrophobic forces in peptide-protein interactions in various fields of life sciences, such as immunology, enzymology, receptor binding, and toxicology.
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Affiliation(s)
- T Cserháti
- Central Research Institute for Chemistry, Hungarian Academy of Sciences, Budapest
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42
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Abstract
The determination of the 3-dimensional structure of the influenza virus neuraminidase in 1983 has served as a platform for understanding interactions between antibodies and protein antigens, for investigating antigenic variation in influenza viruses, and for devising new inhibitors of the enzyme. That work is reviewed here, together with more recent developments that have resulted in one of the inhibitors entering clinical trials as an anti-influenza virus drug.
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Affiliation(s)
- P M Colman
- Biomolecular Research Institute, Parkville, Victoria, Australia
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43
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Malby RL, Tulip WR, Harley VR, McKimm-Breschkin JL, Laver WG, Webster RG, Colman PM. The structure of a complex between the NC10 antibody and influenza virus neuraminidase and comparison with the overlapping binding site of the NC41 antibody. Structure 1994; 2:733-46. [PMID: 7994573 DOI: 10.1016/s0969-2126(00)00074-5] [Citation(s) in RCA: 131] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND While it is well known that different antibodies can be produced against a particular antigen, and even against a particular site on an antigen, up until now there have been no structural studies of cross-reacting antibodies of this type. One antibody-antigen complex whose structure is known is that of the influenza virus antigen, neuraminidase, in complex with the NC41 antibody. Another anti-neuraminidase antibody, NC10, binds to an overlapping site on the antigen. The structure of the complex formed by this antibody with neuraminidase is described here and compared with the NC41-containing complex. RESULTS The crystal structure of the NC10 Fab-neuraminidase complex has been refined to a nominal resolution of 2.5A. Approximately 80% of the binding site of the NC10 antibody on neuraminidase overlaps with that of the NC41 antibody. The epitope residues of neuraminidase are often engaged in quite different interactions with the two antibodies. Although the NC10 and NC41 antibodies have identical amino acid sequences within the first complementarity determining region of their heavy chains, this is not the basis of the cross-reaction. CONCLUSIONS The capacity of two different proteins to bind to the same target structure on a third protein need not be based on the existence of identical or homologous amino acid sequences within those proteins. As we have demonstrated, amino acid residues on the common target structure may be in quite different chemical environments, and may also adopt different conformations within two protein-protein complexes.
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Affiliation(s)
- R L Malby
- Biomolecular Research Institute, Parkville, Victoria, Australia
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44
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Tulip WR, Harley VR, Webster RG, Novotny J. N9 neuraminidase complexes with antibodies NC41 and NC10: empirical free energy calculations capture specificity trends observed with mutant binding data. Biochemistry 1994; 33:7986-97. [PMID: 7517697 DOI: 10.1021/bi00192a002] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
X-ray crystallographic coordinates of influenza virus N9 neuraminidase complexed with monoclonal antibodies NC41 and NC10 [Tulip et al. (1992) J. Mol. Biol. 227, 122-148] served as a starting point for calculations aimed at estimating free energy changes (delta G) of complex formation between the two antibodies and the neuraminidase. Using an empirical function incorporating hydrophobic, electrostatic, and conformational entropy effects, we estimated contributions individual neuraminidase residues make to complex formation (delta G(residue)) and compared the calculated values to experimentally measured differences in antibody binding between the wild-type and mutated neuraminidases [Nuss et al. (1993) Proteins 15, 121-132; calculations done without prior knowledge of the experimental data]. A good correspondence was found between the calculated delta G(residue) values and the mutant binding data in that side chains with large calculated delta G contributions (delta G(residue) < -1 kcal/mol) lie at sites of mutation which cause a marked reduction in antibody binding, and side chains for which delta G(residue) > -1 kcal/mol are sites at which a mutation does not have a marked effect on binding. Because most of the delta G(residue) < -1 kcal/mol side chains also make hydrogen bonds/salt bridges with the antibody, the correspondence of the effect of antibody binding with these electrostatic interactions (18 out of 27 for NC41 and, tentatively, 5 out of 7 for NC10) is about as good as that with predicted energetic residues. All the delta G(residue) < -1 kcal/mol neuraminidase side chains cluster around the most protruding surface regions and are thus spread over different epitope segments. Surprisingly, different residues were found to make the most critical contributions to the NC41 and NC10 complex stabilities despite the fact that the NC41 and NC10 antigenic epitopes overlap, having approximately 70% of surface residues in common. It is thus possible, for two different antibodies, to recognize the same protein surface in strikingly different ways. As only a fraction of the neuraminidase residues appear to make large contributions to antibody binding, the results also support the hypothesis of a "functional" epitope in antigen-antibody interactions. Positive trends between both backbone rigidity and residue accessibility in the complexed state, and contributions of these residues to binding, were also observed for the NC41 complex.
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Affiliation(s)
- W R Tulip
- CSIRO Division of Biomolecular Engineering, Parkville, Victoria, Australia
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45
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Abstract
The structures of the various regions of an antibody molecule are analysed and correlated with biological function. The structural features which relate to potential applications are detailed.
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Affiliation(s)
- E A Padlan
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
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46
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Gruen LC, McKimm-Breschkin JL, Caldwell JB, Nice EC. Affinity ranking of influenza neuraminidase mutants with monoclonal antibodies using an optical biosensor. Comparison with ELISA and slot blot assays. J Immunol Methods 1994; 168:91-100. [PMID: 8288899 DOI: 10.1016/0022-1759(94)90213-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A recently developed alternative to the more traditional techniques for studying antigen-antibody interactions has been examined. This method involves the use of an optical biosensor employing surface plasmon resonance detection. In this system one of the reactants is immobilized on the sensor surface and other reactants are passed over the sensor surface sequentially at a constant flow rate. Binding phenomena are detected in real time from changes in the angle at which surface plasmon resonance occurs. This is dependent, among other things, on changes in the refractive index (which is directly proportional to the mass) at or near to the sensor surface. Applications of this biosensor technique for comparing the binding of related neuraminidases, purified from escape mutants of influenza virus NWS/G70C/75 (N9), to two antibody Fab fragments, are described. These results were compared with those obtained from ELISA and slot blot assays on the same neuraminidases interacting with the same two monoclonal antibodies. The biosensor method was shown to be highly specific, permitting rapid screening of binding in such antigen-antibody systems.
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Affiliation(s)
- L C Gruen
- CSIRO Division of Biomolecular Engineering, Parkville, Victoria, Australia
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47
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Chang CY, Jeffrey PD, Bajorath J, Hellström I, Hellström KE, Sheriff S. Crystallization and preliminary X-ray analysis of the monoclonal anti-tumor antibody BR96 and its complex with the Lewis Y determinant. J Mol Biol 1994; 235:372-6. [PMID: 8289260 DOI: 10.1016/s0022-2836(05)80044-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The monoclonal anti-tumor antibody BR96 binds a tetrasaccharide, Lewis y (Le(y)), in vitro and recognizes a Le(y)-bearing or Le(y)-related tumor-associated antigen in vivo. The Fab of the murine monoclonal antibody, mBR96 (IgG3, kappa), and the Fab' of its human chimera, cBR96 (IgG1, kappa), and their complexes with Le(y) have been screened for crystallization conditions. Crystals suitable for X-ray diffraction have been obtained for uncomplexed cBR96 Fab', cBR96 Fab' in complex with Le(y) and mBR96 Fab in complex with Le(y). The symmetry of the cBR96 Fab' crystals is consistent with space group P2(1)2(1)2, a = 61.1 A; b = 174.3 A; c = 45.6 A; the symmetry of the cBR96 Fab'-Le(y) complex crystals with space group P4(3)2(1)2 (or its enantiomorph), a = b = 82.2 A; c = 167.1 A and the symmetry of the mBR96 Fab-Le(y) complex crystals with space group P2(1)2(1)2(1), a = 69.4 A; b = 84.9 A; c = 86.8 A.
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Affiliation(s)
- C Y Chang
- Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, NJ 08543-4000
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48
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Colman PM. Effects of amino acid sequence changes on antibody-antigen interactions. RESEARCH IN IMMUNOLOGY 1994; 145:33-6. [PMID: 7516563 DOI: 10.1016/s0923-2494(94)80039-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- P M Colman
- Biomolecular Research Institute, Parkville, Australia
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49
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Cherfils J, Bizebard T, Knossow M, Janin J. Rigid-body docking with mutant constraints of influenza hemagglutinin with antibody HC19. Proteins 1994; 18:8-18. [PMID: 7511810 DOI: 10.1002/prot.340180104] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
An automatic docking algorithm has been applied to the modeling of the complex between hemagglutinin from influenza virus and the Fab fragment of a monoclonal antibody raised against this antigen. We have introduced here the use of biochemical information provided by mutants of hemagglutinin. The docking procedure finds a small number of candidate solutions where three sites of escape mutations are buried and form hydrogen bonds in the interface. The localization of the epitope is improved by additional biochemical data about mutants that do not affect antibody binding. Five candidate solutions with low energy, reasonably well-packed interfaces, and six to ten hydrogen bonds are compatible with mutant information. One of the five stands out as generally better than the others from these points of views.
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Affiliation(s)
- J Cherfils
- Laboratoire de Biologie Structurale, UMR 9920, CNRS-Université Paris Sud, Gil-sur-Yvette, France
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50
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Smith-Gill SJ. Protein epitopes: functional vs. structural definitions. RESEARCH IN IMMUNOLOGY 1994; 145:67-70. [PMID: 7516566 DOI: 10.1016/s0923-2494(94)80047-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- S J Smith-Gill
- Laboratory of Genetics, National Cancer Institute, Bethesda, MD 20892
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