1
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Mattos MS, Vandendriessche S, Waisman A, Marques PE. The immunology of B-1 cells: from development to aging. Immun Ageing 2024; 21:54. [PMID: 39095816 PMCID: PMC11295433 DOI: 10.1186/s12979-024-00455-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Accepted: 07/17/2024] [Indexed: 08/04/2024]
Abstract
B-1 cells have intricate biology, with distinct function, phenotype and developmental origin from conventional B cells. They generate a B cell receptor with conserved germline characteristics and biased V(D)J recombination, allowing this innate-like lymphocyte to spontaneously produce self-reactive natural antibodies (NAbs) and become activated by immune stimuli in a T cell-independent manner. NAbs were suggested as "rheostats" for the chronic diseases in advanced age. In fact, age-dependent loss of function of NAbs has been associated with clinically-relevant diseases in the elderly, such as atherosclerosis and neurodegenerative disorders. Here, we analyzed comprehensively the ontogeny, phenotypic characteristics, functional properties and emerging roles of B-1 cells and NAbs in health and disease. Additionally, after navigating through the complexities of B-1 cell biology from development to aging, therapeutic opportunities in the field are discussed.
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Affiliation(s)
- Matheus Silvério Mattos
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000, Louvain, Belgium
| | - Sofie Vandendriessche
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000, Louvain, Belgium
| | - Ari Waisman
- Institute for Molecular Medicine, University Medical Centre of the Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Pedro Elias Marques
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000, Louvain, Belgium.
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2
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Zhao G, Richaud AD, Williamson RT, Feig M, Roche SP. De Novo Synthesis and Structural Elucidation of CDR-H3 Loop Mimics. ACS Chem Biol 2024; 19:1583-1592. [PMID: 38916527 PMCID: PMC11299430 DOI: 10.1021/acschembio.4c00236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
The binding affinity of antibodies to specific antigens stems from a remarkably broad repertoire of hypervariable loops known as complementarity-determining regions (CDRs). While recognizing the pivotal role of the heavy-chain 3 CDRs (CDR-H3s) in maximizing antibody-antigen affinity and specificity, the key structural determinants responsible for their adaptability to diverse loop sequences, lengths, and noncanonical structures are hitherto unknown. To address this question, we achieved a de novo synthesis of bulged CDR-H3 mimics excised from their full antibody context. CD and NMR data revealed that these stable standalone β-hairpin scaffolds are well-folded and retain many of the native bulge CDR-H3 features in water. In particular, the tryptophan residue, highly conserved across CDR-H3 sequences, was found to extend the kinked base of these β-bulges through a combination of stabilizing intramolecular hydrogen bond and CH/π interaction. The structural ensemble consistent with our NMR observations exposed the dynamic nature of residues at the base of the loop, suggesting that β-bulges act as molecular hinges connecting the rigid stem to the more flexible loops of CDR-H3s. We anticipate that this deeper structural understanding of CDR-H3s will lay the foundation to inform the design of antibody drugs broadly and engineer novel CDR-H3 peptide scaffolds as therapeutics.
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Affiliation(s)
- Guangkuan Zhao
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, United States
| | - Alexis D. Richaud
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, United States
| | - R. Thomas Williamson
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, NC 28409, United States
| | - Michael Feig
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, United States
| | - Stéphane P. Roche
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, United States
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3
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Tulika T, Pedersen RW, Rimbault C, Ahmadi S, Rivera‐de‐Torre E, Fernández‐Quintero ML, Loeffler JR, Bohn M, Ljungars A, Ledsgaard L, Voldborg BG, Ruso‐Julve F, Andersen JT, Laustsen AH. Phage display assisted discovery of a pH-dependent anti-α-cobratoxin antibody from a natural variable domain library. Protein Sci 2023; 32:e4821. [PMID: 37897425 PMCID: PMC10659949 DOI: 10.1002/pro.4821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 09/28/2023] [Accepted: 10/24/2023] [Indexed: 10/30/2023]
Abstract
Recycling IgG antibodies bind to their target antigen at physiological pH in the blood stream and release them upon endocytosis when pH levels drop, allowing the IgG antibodies to be recycled into circulation via FcRn-mediated cellular pathways, while the antigens undergo lysosomal degradation. This enables recycling antibodies to achieve comparable therapeutic effect at lower doses than their non-recycling counterparts. The development of such antibodies is typically achieved by histidine doping of their variable regions or by performing in vitro antibody selection campaigns utilizing histidine doped libraries. Both are strategies that may introduce sequence liabilities. Here, we present a methodology that employs a naïve antibody phage display library, consisting of natural variable domains, to discover antibodies that bind α-cobratoxin from the venom of Naja kaouthia in a pH-dependent manner. As a result, an antibody was discovered that exhibits a 7-fold higher off-rate at pH 5.5 than pH 7.4 in bio-layer interferometry experiments. Interestingly, no histidine residues were found in its variable domains, and in addition, the antibody showed pH-dependent binding to a histidine-devoid antigen mutant. As such, the results demonstrate that pH-dependent antigen-antibody binding may not always be driven by histidine residues. By employing molecular dynamics simulations, different protonation states of titratable residues were found, which potentially could be responsible for the observed pH-dependent antigen binding properties of the antibody. Finally, given the typically high diversity of naïve antibody libraries, the methodology presented here can likely be applied to discover recycling antibodies against different targets ab initio without the need for histidine doping.
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Affiliation(s)
- Tulika Tulika
- Department of Biotechnology and BiomedicineTechnical University of DenmarkLyngbyDenmark
| | - Rasmus W. Pedersen
- Department of Biotechnology and BiomedicineTechnical University of DenmarkLyngbyDenmark
| | - Charlotte Rimbault
- Department of Biotechnology and BiomedicineTechnical University of DenmarkLyngbyDenmark
| | - Shirin Ahmadi
- Department of Biotechnology and BiomedicineTechnical University of DenmarkLyngbyDenmark
| | | | - Monica L. Fernández‐Quintero
- Center for Molecular Biosciences Innsbruck, Department of GeneralInorganic and Theoretical Chemistry, University of InnsbruckInnsbruckAustria
| | - Johannes R. Loeffler
- Center for Molecular Biosciences Innsbruck, Department of GeneralInorganic and Theoretical Chemistry, University of InnsbruckInnsbruckAustria
| | - Markus‐Frederik Bohn
- Department of Biotechnology and BiomedicineTechnical University of DenmarkLyngbyDenmark
| | - Anne Ljungars
- Department of Biotechnology and BiomedicineTechnical University of DenmarkLyngbyDenmark
| | - Line Ledsgaard
- Department of Biotechnology and BiomedicineTechnical University of DenmarkLyngbyDenmark
| | - Bjørn G. Voldborg
- Department of Biotechnology and BiomedicineTechnical University of DenmarkLyngbyDenmark
| | - Fulgencio Ruso‐Julve
- Department of PharmacologyUniversity of OsloOsloNorway
- Department of ImmunologyOslo University Hospital RikshospitaletOsloNorway
- Precision Immunotherapy AllianceUniversity of OsloOsloNorway
| | - Jan Terje Andersen
- Department of PharmacologyUniversity of OsloOsloNorway
- Department of ImmunologyOslo University Hospital RikshospitaletOsloNorway
- Precision Immunotherapy AllianceUniversity of OsloOsloNorway
| | - Andreas H. Laustsen
- Department of Biotechnology and BiomedicineTechnical University of DenmarkLyngbyDenmark
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4
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Borowska MT, Boughter CT, Bunker JJ, Guthmiller JJ, Wilson PC, Roux B, Bendelac A, Adams EJ. Biochemical and biophysical characterization of natural polyreactivity in antibodies. Cell Rep 2023; 42:113190. [PMID: 37804505 PMCID: PMC10858392 DOI: 10.1016/j.celrep.2023.113190] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 08/25/2023] [Accepted: 09/14/2023] [Indexed: 10/09/2023] Open
Abstract
To become specialized binders, antibodies undergo a process called affinity maturation to maximize their binding affinity. Despite this process, some antibodies retain low-affinity binding to diverse epitopes in a phenomenon called polyreactivity. Here we seek to understand the molecular basis of this polyreactivity in antibodies. Our results highlight that polyreactive antigen-binding fragments (Fabs) bind their targets with low affinities, comparable to T cell receptor recognition of autologous classical major histocompatibility complex. Extensive mutagenic studies find no singular amino acid residue or biochemical property responsible for polyreactive interaction, suggesting that polyreactive antibodies use multiple strategies for engagement. Finally, our crystal structures and all-atom molecular dynamics simulations of polyreactive Fabs show increased rigidity compared to their monoreactive relatives, forming a neutral and accessible platform for diverse antigens to bind. Together, these data support a cooperative strategy of rigid neutrality in establishing the polyreactive status of an antibody molecule.
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Affiliation(s)
- Marta T Borowska
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | | | - Jeffrey J Bunker
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Jenna J Guthmiller
- Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL 60637, USA
| | - Patrick C Wilson
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL 60637, USA
| | - Benoit Roux
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Albert Bendelac
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Erin J Adams
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA; Committee on Immunology, University of Chicago, Chicago, IL 60637, USA.
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5
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Fernández-Quintero ML, Pomarici ND, Fischer ALM, Hoerschinger VJ, Kroell KB, Riccabona JR, Kamenik AS, Loeffler JR, Ferguson JA, Perrett HR, Liedl KR, Han J, Ward AB. Structure and Dynamics Guiding Design of Antibody Therapeutics and Vaccines. Antibodies (Basel) 2023; 12:67. [PMID: 37873864 PMCID: PMC10594513 DOI: 10.3390/antib12040067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 10/10/2023] [Accepted: 10/13/2023] [Indexed: 10/25/2023] Open
Abstract
Antibodies and other new antibody-like formats have emerged as one of the most rapidly growing classes of biotherapeutic proteins. Understanding the structural features that drive antibody function and, consequently, their molecular recognition is critical for engineering antibodies. Here, we present the structural architecture of conventional IgG antibodies alongside other formats. We emphasize the importance of considering antibodies as conformational ensembles in solution instead of focusing on single-static structures because their functions and properties are strongly governed by their dynamic nature. Thus, in this review, we provide an overview of the unique structural and dynamic characteristics of antibodies with respect to their antigen recognition, biophysical properties, and effector functions. We highlight the numerous technical advances in antibody structure prediction and design, enabled by the vast number of experimentally determined high-quality structures recorded with cryo-EM, NMR, and X-ray crystallography. Lastly, we assess antibody and vaccine design strategies in the context of structure and dynamics.
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Affiliation(s)
- Monica L. Fernández-Quintero
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Nancy D. Pomarici
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Anna-Lena M. Fischer
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Valentin J. Hoerschinger
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Katharina B. Kroell
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Jakob R. Riccabona
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Anna S. Kamenik
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Johannes R. Loeffler
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - James A. Ferguson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Hailee R. Perrett
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Klaus R. Liedl
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Julianna Han
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Andrew B. Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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6
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Hoffstedt M, Stein MO, Baumann K, Wätzig H. Experimentally Observed Conformational Changes in Antibodies Due to Binding and Paratope-epitope Asymmetries. J Pharm Sci 2023; 112:2404-2411. [PMID: 37295605 DOI: 10.1016/j.xphs.2023.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 06/02/2023] [Accepted: 06/02/2023] [Indexed: 06/12/2023]
Abstract
Understanding binding related changes in antibody conformations is important for epitope prediction and antibody refinement. The increase of available data in the PDB allowed a more detailed investigation of the conformational landscape for free and bound antibodies. A dataset containing a total of 835 unique PDB entries of antibodies that were crystallized in complex with their antigen and in a free state was constructed. It was examined for binding related conformation changes. We present further evidence supporting the theory of a pre-existing-equilibrium in experimental data. Multiple sequence alignments did not show binding induced tendencies in the solvent accessibility of residues in any specific position. Evaluating the changes in solvent accessibility per residue revealed a certain binding induced increase for several amino acids. Antibody-antigen interaction statistics were established and quantify a significant directional asymmetry between many interacting antibody and antigen residue pairs, especially a richness in tyrosine in the antibody epitope compared to its paratope. This asymmetry could potentially facilitate an increase in the success rate of computationally guided antibody refinement.
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Affiliation(s)
- Marc Hoffstedt
- Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Deutschland
| | - Matthias Oliver Stein
- Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Deutschland
| | - Knut Baumann
- Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Deutschland
| | - Hermann Wätzig
- Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Deutschland
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7
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Maeta S, Nakakido M, Matsuura H, Sakai N, Hirata K, Kuroda D, Fukunaga A, Tsumoto K. Arginine cluster introduction on framework region in anti-lysozyme antibody improved association rate constant by changing conformational diversity of CDR loops. Protein Sci 2023; 32:e4745. [PMID: 37550885 PMCID: PMC10461459 DOI: 10.1002/pro.4745] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 05/30/2023] [Accepted: 08/01/2023] [Indexed: 08/09/2023]
Abstract
Antibodies are used for many therapeutic and biotechnological purposes. Because the affinity of an antibody to the antigen is critical for clinical efficacy of pharmaceuticals, many affinity maturation strategies have been developed. Although we previously reported an affinity maturation strategy in which the association rate of the antibody toward its antigen is improved by introducing a cluster of arginine residues into the framework region of the antibody, the detailed molecular mechanism responsible for this improvement has been unknown. In this study, we introduced five arginine residues into an anti-hen egg white lysozyme antibody (HyHEL10) Fab fragment to create the R5-mutant and comprehensively characterized the interaction between antibody and antigen using thermodynamic analysis, X-ray crystallography, and molecular dynamics (MD) simulations. Our results indicate that introduction of charged residues strongly enhanced the association rate, as previously reported, and the antibody-antigen complex structure was almost the same for the R5-mutant and wild-type Fabs. The MD simulations indicate that the mutation increased conformational diversity in complementarity-determining region loops and thereby enhanced the association rate. These observations provide the molecular basis of affinity maturation by R5 mutation.
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Affiliation(s)
- Shingo Maeta
- Bio‐Diagnostic Reagent Technology CenterSysmex CorporationKobeJapan
- Department of Bioengineering, School of EngineeringThe University of TokyoTokyoJapan
| | - Makoto Nakakido
- Department of Bioengineering, School of EngineeringThe University of TokyoTokyoJapan
- Department of Chemistry and Biotechnology, Graduate School of EngineeringThe University of TokyoTokyoJapan
| | - Hiroaki Matsuura
- Life Science Research Infrastructure Group, RIKEN SPring‐8 CenterSaitamaJapan
| | - Naoki Sakai
- Life Science Research Infrastructure Group, RIKEN SPring‐8 CenterSaitamaJapan
| | - Kunio Hirata
- Life Science Research Infrastructure Group, RIKEN SPring‐8 CenterSaitamaJapan
| | - Daisuke Kuroda
- Department of Bioengineering, School of EngineeringThe University of TokyoTokyoJapan
- Department of Chemistry and Biotechnology, Graduate School of EngineeringThe University of TokyoTokyoJapan
- Research Center for Drug and Vaccine DevelopmentNational Institute of Infectious DiseasesTokyoJapan
| | - Atsushi Fukunaga
- Bio‐Diagnostic Reagent Technology CenterSysmex CorporationKobeJapan
| | - Kouhei Tsumoto
- Department of Bioengineering, School of EngineeringThe University of TokyoTokyoJapan
- Department of Chemistry and Biotechnology, Graduate School of EngineeringThe University of TokyoTokyoJapan
- Institute of Medical ScienceThe University of TokyoTokyoJapan
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8
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Rappazzo CG, Fernández-Quintero ML, Mayer A, Wu NC, Greiff V, Guthmiller JJ. Defining and Studying B Cell Receptor and TCR Interactions. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 211:311-322. [PMID: 37459189 PMCID: PMC10495106 DOI: 10.4049/jimmunol.2300136] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 04/15/2023] [Indexed: 07/20/2023]
Abstract
BCRs (Abs) and TCRs (or adaptive immune receptors [AIRs]) are the means by which the adaptive immune system recognizes foreign and self-antigens, playing an integral part in host defense, as well as the emergence of autoimmunity. Importantly, the interaction between AIRs and their cognate Ags defies a simple key-in-lock paradigm and is instead a complex many-to-many mapping between an individual's massively diverse AIR repertoire, and a similarly diverse antigenic space. Understanding how adaptive immunity balances specificity with epitopic coverage is a key challenge for the field, and terms such as broad specificity, cross-reactivity, and polyreactivity remain ill-defined and are used inconsistently. In this Immunology Notes and Resources article, a group of experimental, structural, and computational immunologists define commonly used terms associated with AIR binding, describe methodologies to study these binding modes, as well as highlight the implications of these different binding modes for therapeutic design.
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Affiliation(s)
| | | | - Andreas Mayer
- Division of Infection and Immunity, University College London, London WC1E 6BT, UK
| | - Nicholas C. Wu
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Victor Greiff
- Department of Immunology, University of Oslo and Oslo University Hospital, 0372 Oslo, Norway
| | - Jenna J. Guthmiller
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
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9
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Guloglu B, Deane CM. Specific attributes of the V L domain influence both the structure and structural variability of CDR-H3 through steric effects. Front Immunol 2023; 14:1223802. [PMID: 37564639 PMCID: PMC10410447 DOI: 10.3389/fimmu.2023.1223802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 06/28/2023] [Indexed: 08/12/2023] Open
Abstract
Antibodies, through their ability to target virtually any epitope, play a key role in driving the adaptive immune response in jawed vertebrates. The binding domains of standard antibodies are their variable light (VL) and heavy (VH) domains, both of which present analogous complementarity-determining region (CDR) loops. It has long been known that the VH CDRs contribute more heavily to the antigen-binding surface (paratope), with the CDR-H3 loop providing a major modality for the generation of diverse paratopes. Here, we provide evidence for an additional role of the VL domain as a modulator of CDR-H3 structure, using a diverse set of antibody crystal structures and a large set of molecular dynamics simulations. We show that specific attributes of the VL domain such as subtypes, CDR canonical forms and genes can influence the structural diversity of the CDR-H3 loop, and provide a physical model for how this effect occurs through inter-loop contacts and packing of CDRs against each other. Our results indicate that the rigid minor loops fine-tune the structure of CDR-H3, thereby contributing to the generation of surfaces complementary to the vast number of possible epitope topologies, and provide insights into the interdependent nature of CDR conformations, an understanding of which is important for the rational antibody design process.
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Affiliation(s)
- Bora Guloglu
- Oxford Protein Informatics Group, Department of Statistics, University of Oxford, Oxford, United Kingdom
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, United Kingdom
| | - Charlotte M. Deane
- Oxford Protein Informatics Group, Department of Statistics, University of Oxford, Oxford, United Kingdom
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10
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Structural mechanism of Fab domain dissociation as a measure of interface stability. J Comput Aided Mol Des 2023; 37:201-215. [PMID: 36918473 PMCID: PMC10049950 DOI: 10.1007/s10822-023-00501-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 02/23/2023] [Indexed: 03/16/2023]
Abstract
Therapeutic antibodies should not only recognize antigens specifically, but also need to be free from developability issues, such as poor stability. Thus, the mechanistic understanding and characterization of stability are critical determinants for rational antibody design. In this study, we use molecular dynamics simulations to investigate the melting process of 16 antigen binding fragments (Fabs). We describe the Fab dissociation mechanisms, showing a separation in the VH-VL and in the CH1-CL domains. We found that the depths of the minima in the free energy curve, corresponding to the bound states, correlate with the experimentally determined melting temperatures. Additionally, we provide a detailed structural description of the dissociation mechanism and identify key interactions in the CDR loops and in the CH1-CL interface that contribute to stabilization. The dissociation of the VH-VL or CH1-CL domains can be represented by conformational changes in the bend angles between the domains. Our findings elucidate the melting process of antigen binding fragments and highlight critical residues in both the variable and constant domains, which are also strongly germline dependent. Thus, our proposed mechanisms have broad implications in the development and design of new and more stable antigen binding fragments.
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11
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Nosrati M, Housaindokht MR. New insights into the effect of mutations on affibody-Fc interaction, a molecular dynamics simulation approach. J Struct Biol 2023; 215:107925. [PMID: 36470559 DOI: 10.1016/j.jsb.2022.107925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 11/24/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022]
Abstract
Staphylococcal protein A (SpA) domain B (the basis of affibody) has been widely used in affinity chromatography and found therapeutic applications against inflammatory diseases through targeting the Fc part of immunoglobulin G (IgG). We have performed extensive molecular dynamics simulation of 41 SpA mutants and compared their dynamics and conformations to wild type. The simulations revealed the molecular details of structural and dynamics changes that occurred due to introducing point mutations and helped to explain the SPR results. It was observed in some variants a point mutation caused extensive structural changes far from the mutation site, while an effect of some other mutations was limited to the site of the mutated residue. Also, the pattern of hydrogen bond networks and hydrophobic core arrangements were investigated. We figured out mutations that occurred at positions 128, 136, 150 and 153, affected two hydrophobic cores at the interface as well as mutations introduced at positions 129 and 154 interrupted two hydrogen bond networks of the interface, SPR data showed all of these mutations reduced binding affinity significantly. Overall, by scanning the SpA-Fc interface through the large numbers of introduced mutations, the new insights have been gained which would help to design high- affinity ligands of IgG.
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Affiliation(s)
- Masoumeh Nosrati
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran; Department of Cell and Molecular Biology, Uppsala University, BMC, Uppsala, Sweden.
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12
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Seidler CA, Kokot J, Fernández-Quintero ML, Liedl KR. Structural Characterization of Nanobodies during Germline Maturation. Biomolecules 2023; 13:380. [PMID: 36830754 PMCID: PMC9953242 DOI: 10.3390/biom13020380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/27/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
Camelid heavy-chain antibody variable domains (VHH), nanobodies, are the smallest-known functional antibody fragments with high therapeutic potential. In this study, we investigate a VHH binding to hen egg-white lysozyme (HEL). We structurally and dynamically characterized the conformational diversity of four VHH variants to elucidate the antigen-binding process. For two of these antibodies, not only are the dissociation constants known, but also the experimentally determined crystal structures of the VHH in complex with HEL are available. We performed well-tempered metadynamics simulations in combination with molecular dynamics simulations to capture a broad conformational space and to reconstruct the thermodynamics and kinetics of conformational transitions in the antigen-binding site, the paratope. By kinetically characterizing the loop movements of the paratope, we found that, with an increase in affinity, the state populations shift towards the binding competent conformation. The contacts contributing to antigen binding, and those who contribute to the overall stability, show a clear trend towards less variable but more intense contacts. Additionally, these investigated nanobodies clearly follow the conformational selection paradigm, as the binding competent conformation pre-exists within the structural ensembles without the presence of the antigen.
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Affiliation(s)
| | | | - Monica L. Fernández-Quintero
- Department of General, Inorganic and Theoretical Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, 6020 Innsbruck, Austria
| | - Klaus R. Liedl
- Department of General, Inorganic and Theoretical Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, 6020 Innsbruck, Austria
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13
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Aguilar MF, Garay AS, Attallah C, Rodrigues DE, Oggero M. Changes in antibody binding and functionality after humanizing a murine scFv anti-IFN-α2: From in silico studies to experimental analysis. Mol Immunol 2022; 151:193-203. [PMID: 36166900 DOI: 10.1016/j.molimm.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 08/21/2022] [Accepted: 09/11/2022] [Indexed: 11/26/2022]
Abstract
The structural and dynamic changes introduced during antibody humanization continue to be a topic open to new contributions. For this reason, the study of structural and functional changes of a murine scFv (mu.scFv) anti-rhIFN-α2b after humanization was carried out. As it was shown by long molecular dynamics simulations and circular dichroism analysis, changes in primary sequence affected the tertiary structure of the humanized scFv (hz.scFv): the position of the variable domain of light chain (VL) respective to the variable domain of heavy chain (VH) in each scFv molecule was different. This change mainly impacted on conformation and dynamics of the complementarity-determining region 3 of VH (CDR-H3) which led to changes in the specificity and affinity of humanized scFv (hz.scFv). These observations agree with experimental results that showed a decrease in the antigen-binding strength of hz.scFv, and different capacities of these molecules to neutralize the in vitro rhIFN-α2b biological activity. Besides, experimental studies to characterize antigen-antibody binding showed that mu.scFv and hz.scFv bind to the same antigen area and recognize a conformational epitope, which is evidence of docking results. Finally, the differences between these molecules to neutralize the in vitro rhIFN-α2b biological activity were described as a consequence of the blockade of certain functionally relevant amino acids of the cytokine, after scFv binding. All these observations confirmed that humanization affected the affinity and specificity of hz.scFv and pointed out that two specific changes in the frameworks would be responsible.
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Affiliation(s)
- María Fernanda Aguilar
- UNL, CONICET, FBCB, Centro Biotecnológico del Litoral, Santa Fe, Pcia. Santa Fe S3000ZAA, Argentina
| | - A Sergio Garay
- UNL, FBCB, Departamento de Física, Ciudad Universitaria UNL, Pje. "El Pozo" - C.C. 242, S3000ZAA Santa Fe, Argentina.
| | - Carolina Attallah
- UNL, CONICET, FBCB, Centro Biotecnológico del Litoral, Santa Fe, Pcia. Santa Fe S3000ZAA, Argentina
| | - Daniel E Rodrigues
- UNL, FBCB, Departamento de Física, Ciudad Universitaria UNL, Pje. "El Pozo" - C.C. 242, S3000ZAA Santa Fe, Argentina; INTEC, CONICET-UNL, Predio CONICET Santa Fe, Pje. "El Pozo", S3000 Santa Fe, Argentina
| | - Marcos Oggero
- UNL, CONICET, FBCB, Centro Biotecnológico del Litoral, Santa Fe, Pcia. Santa Fe S3000ZAA, Argentina.
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14
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Löhr T, Sormanni P, Vendruscolo M. Conformational Entropy as a Potential Liability of Computationally Designed Antibodies. Biomolecules 2022; 12:718. [PMID: 35625644 PMCID: PMC9138470 DOI: 10.3390/biom12050718] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 05/06/2022] [Accepted: 05/08/2022] [Indexed: 01/28/2023] Open
Abstract
In silico antibody discovery is emerging as a viable alternative to traditional in vivo and in vitro approaches. Many challenges, however, remain open to enabling the properties of designed antibodies to match those produced by the immune system. A major question concerns the structural features of computer-designed complementarity determining regions (CDRs), including the role of conformational entropy in determining the stability and binding affinity of the designed antibodies. To address this problem, we used enhanced-sampling molecular dynamics simulations to compare the free energy landscapes of single-domain antibodies (sdAbs) designed using structure-based (DesAb-HSA-D3) and sequence-based approaches (DesAbO), with that of a nanobody derived from llama immunization (Nb10). Our results indicate that the CDR3 of DesAbO is more conformationally heterogeneous than those of both DesAb-HSA-D3 and Nb10, and the CDR3 of DesAb-HSA-D3 is slightly more dynamic than that of Nb10, which is the original scaffold used for the design of DesAb-HSA-D3. These differences underline the challenges in the rational design of antibodies by revealing the presence of conformational substates likely to have different binding properties and to generate a high entropic cost upon binding.
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Affiliation(s)
| | | | - Michele Vendruscolo
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK; (T.L.); (P.S.)
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15
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Nanobody Paratope Ensembles in Solution Characterized by MD Simulations and NMR. Int J Mol Sci 2022; 23:ijms23105419. [PMID: 35628231 PMCID: PMC9141556 DOI: 10.3390/ijms23105419] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/02/2022] [Accepted: 05/10/2022] [Indexed: 01/27/2023] Open
Abstract
Variable domains of camelid antibodies (so-called nanobodies or VHH) are the smallest antibody fragments that retain complete functionality and therapeutic potential. Understanding of the nanobody-binding interface has become a pre-requisite for rational antibody design and engineering. The nanobody-binding interface consists of up to three hypervariable loops, known as the CDR loops. Here, we structurally and dynamically characterize the conformational diversity of an anti-GFP-binding nanobody by using molecular dynamics simulations in combination with experimentally derived data from nuclear magnetic resonance (NMR) spectroscopy. The NMR data contain both structural and dynamic information resolved at various timescales, which allows an assessment of the quality of protein MD simulations. Thus, in this study, we compared the ensembles for the anti-GFP-binding nanobody obtained from MD simulations with results from NMR. We find excellent agreement of the NOE-derived distance maps obtained from NMR and MD simulations and observe similar conformational spaces for the simulations with and without NOE time-averaged restraints. We also compare the measured and calculated order parameters and find generally good agreement for the motions observed in the ps–ns timescale, in particular for the CDR3 loop. Understanding of the CDR3 loop dynamics is especially critical for nanobodies, as this loop is typically critical for antigen recognition.
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16
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DeLaitsch AT, Pridgen JR, Tytla A, Peach ML, Hu R, Farnsworth DW, McMillan AK, Flanagan N, Temme JS, Nicklaus MC, Gildersleeve JC. Selective Recognition of Carbohydrate Antigens by Germline Antibodies Isolated from AID Knockout Mice. J Am Chem Soc 2022; 144:4925-4941. [PMID: 35282679 PMCID: PMC10506689 DOI: 10.1021/jacs.1c12745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Germline antibodies, the initial set of antibodies produced by the immune system, are critical for host defense, and information about their binding properties can be useful for designing vaccines, understanding the origins of autoantibodies, and developing monoclonal antibodies. Numerous studies have found that germline antibodies are polyreactive with malleable, flexible binding pockets. While insightful, it remains unclear how broadly this model applies, as there are many families of antibodies that have not yet been studied. In addition, the methods used to obtain germline antibodies typically rely on assumptions and do not work well for many antibodies. Herein, we present a distinct approach for isolating germline antibodies that involves immunizing activation-induced cytidine deaminase (AID) knockout mice. This strategy amplifies antigen-specific B cells, but somatic hypermutation does not occur because AID is absent. Using synthetic haptens, glycoproteins, and whole cells, we obtained germline antibodies to an assortment of clinically important tumor-associated carbohydrate antigens, including Lewis Y, the Tn antigen, sialyl Lewis C, and Lewis X (CD15/SSEA-1). Through glycan microarray profiling and cell binding, we demonstrate that all but one of these germline antibodies had high selectivity for their glycan targets. Using molecular dynamics simulations, we provide insights into the structural basis of glycan recognition. The results have important implications for designing carbohydrate-based vaccines, developing anti-glycan monoclonal antibodies, and understanding antibody evolution within the immune system.
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Affiliation(s)
- Andrew T DeLaitsch
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Jacey R Pridgen
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Avery Tytla
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Megan L Peach
- Basic Science Program, Chemical Biology Laboratory, Leidos Biomedical Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Rayleen Hu
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - David W Farnsworth
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Aislinn K McMillan
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Natalie Flanagan
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - J Sebastian Temme
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Marc C Nicklaus
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Jeffrey C Gildersleeve
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
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17
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Hsieh YC, Liao JM, Chuang KH, Ho KW, Hong ST, Liu HJ, Huang BC, Chen IJ, Liu YL, Wang JY, Tsai HL, Su YC, Wang YT, Cheng TL. A universal in silico V(D)J recombination strategy for developing humanized monoclonal antibodies. J Nanobiotechnology 2022; 20:58. [PMID: 35101043 PMCID: PMC8805405 DOI: 10.1186/s12951-022-01259-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/12/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Humanization of mouse monoclonal antibodies (mAbs) is crucial for reducing their immunogenicity in humans. However, humanized mAbs often lose their binding affinities. Therefore, an in silico humanization method that can prevent the loss of the binding affinity of mAbs is needed. METHODS We developed an in silico V(D)J recombination platform in which we used V(D)J human germline gene sequences to design five humanized candidates of anti-tumor necrosis factor (TNF)-α mAbs (C1-C5) by using different human germline templates. The candidates were subjected to molecular dynamics simulation. In addition, the structural similarities of their complementarity-determining regions (CDRs) to those of original mouse mAbs were estimated to derive the weighted interatomic root mean squared deviation (wRMSDi) value. Subsequently, the correlation of the derived wRMSDi value with the half maximal effective concentration (EC50) and the binding affinity (KD) of the humanized anti-TNF-α candidates was examined. To confirm whether our in silico estimation method can be used for other humanized mAbs, we tested our method using the anti-epidermal growth factor receptor (EGFR) a4.6.1, anti-glypican-3 (GPC3) YP9.1 and anti-α4β1 integrin HP1/2L mAbs. RESULTS The R2 value for the correlation between the wRMSDi and log(EC50) of the recombinant Remicade and those of the humanized anti-TNF-α candidates was 0.901, and the R2 value for the correlation between wRMSDi and log(KD) was 0.9921. The results indicated that our in silico V(D)J recombination platform could predict the binding affinity of humanized candidates and successfully identify the high-affinity humanized anti-TNF-α antibody (Ab) C1 with a binding affinity similar to that of the parental chimeric mAb (5.13 × 10-10). For the anti-EGFR a4.6.1, anti-GPC3 YP9.1, and anti-α4β1 integrin HP1/2L mAbs, the wRMSDi and log(EC50) exhibited strong correlations (R2 = 0.9908, 0.9999, and 0.8907, respectively). CONCLUSIONS Our in silico V(D)J recombination platform can facilitate the development of humanized mAbs with low immunogenicity and high binding affinities. This platform can directly transform numerous mAbs with therapeutic potential to humanized or even human therapeutic Abs for clinical use.
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Affiliation(s)
- Yuan-Chin Hsieh
- Center for Biomarkers and Biotech Drugs, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan
- School of Medicine for International Students, I-Shou University, No.8, Yida Rd., Jiaosu Village Yanchao District, Kaohsiung, 82445, Taiwan
| | - Jun-Min Liao
- Center for Biomarkers and Biotech Drugs, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan
| | - Kuo-Hsiang Chuang
- Graduate Institute of Pharmacognosy, Taipei Medical University, 250 Wuxing Street, Taipei, 11031, Taiwan
- Ph.D. Program for Clinical Drug Discovery From Botanical Herbs, Taipei Medical University, 250 Wuxing Street, Taipei, 11031, Taiwan
| | - Kai-Wen Ho
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan
| | - Shih-Ting Hong
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan
| | - Hui-Ju Liu
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan
| | - Bo-Cheng Huang
- Institute of Biomedical Sciences, National Sun Yat-Sen University, 70 Lien-hai Road, Kaohsiung, 804, Taiwan
| | - I-Ju Chen
- School of Medicine, I-Shou University, No.8, Yida Rd., Jiaosu Village Yanchao District, Kaohsiung, 82445, Taiwan
| | - Yen-Ling Liu
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan
| | - Jaw-Yuan Wang
- Center for Biomarkers and Biotech Drugs, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan
- Division of Colorectal Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan
- Department of Surgery, Faculty of Medicine, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, No.100, Tzyou 1st Rd., Sanmin Dist., Kaohsiung, 80756, Taiwan
- Center for Cancer Research, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan
| | - Hsiang-Lin Tsai
- Division of Colorectal Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan
- Department of Surgery, Faculty of Medicine, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan
| | - Yu-Cheng Su
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, No. 1001, Daxue Rd. East Dist., Hsin-Chu, 300, Taiwan
| | - Yen-Tseng Wang
- Center for Biomarkers and Biotech Drugs, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan.
- School of Post-Baccalaureate Medicine, College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan.
| | - Tian-Lu Cheng
- Center for Biomarkers and Biotech Drugs, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan.
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, 100 Shih-Chuan First Road, Kaohsiung, 80708, Taiwan.
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18
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Fernández-Quintero ML, Kroell KB, Grunewald LJ, Fischer ALM, Riccabona JR, Liedl KR. CDR loop interactions can determine heavy and light chain pairing preferences in bispecific antibodies. MAbs 2022; 14:2024118. [PMID: 35090383 PMCID: PMC8803122 DOI: 10.1080/19420862.2021.2024118] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
As the current biotherapeutic market is dominated by antibodies, the design of different antibody formats, like bispecific antibodies, is critical to the advancement of the field. In contrast to monovalent antibodies, which consist of two identical antigen-binding sites, bispecific antibodies can target two different epitopes by containing two different antigen-binding sites. Thus, the rise of new formats as successful therapeutics has reignited the interest in advancing and facilitating the efficient production of bispecific antibodies. Here, we investigate the influence of point mutations in the antigen-binding site, the paratope, on heavy and light chain pairing preferences by using molecular dynamics simulations. In agreement with experiments, we find that specific residues in the antibody variable domain (Fv), i.e., the complementarity-determining region (CDR) L3 and H3 loops, determine heavy and light chain pairing preferences. Excitingly, we observe substantial population shifts in CDR-H3 and CDR-L3 loop conformations in solution accompanied by a decrease in bispecific IgG yield. These conformational changes in the CDR3 loops induced by point mutations also influence all other CDR loop conformations and consequentially result in different CDR loop states in solution. However, besides their effect on the obtained CDR loop ensembles, point mutations also lead to distinct interaction patterns in the VH-VL interface. By comparing the interaction patterns among all investigated variants, we observe specific contacts in the interface that drive heavy and light chain pairing. Thus, these findings have broad implications in the field of antibody engineering and design because they provide a mechanistic understanding of antibody interfaces, by identifying critical factors driving the pairing preferences, and thus can help to advance the design of bispecific antibodies.
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Affiliation(s)
- Monica L Fernández-Quintero
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Katharina B Kroell
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Lukas J Grunewald
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Anna-Lena M Fischer
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Jakob R Riccabona
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Klaus R Liedl
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
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19
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Paratope states in solution improve structure prediction and docking. Structure 2021; 30:430-440.e3. [PMID: 34838187 DOI: 10.1016/j.str.2021.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 09/10/2021] [Accepted: 11/03/2021] [Indexed: 12/13/2022]
Abstract
Structure-based antibody design and accurate predictions of antibody-antigen interactions remain major challenges in computational biology. By using molecular dynamics simulations, we show that a single static X-ray structure is not sufficient to identify determinants of antibody-antigen recognition. Here, we investigate antibodies that undergo substantial conformational changes upon antigen binding and have been classified as difficult cases in an extensive benchmark for antibody-antigen docking. We present thermodynamics and transition kinetics of these conformational rearrangements and show that paratope states can be used to improve antibody-antigen docking. By using the unbound antibody X-ray structure as starting structure for molecular dynamics simulations, we retain a binding competent conformation substantially different to the unbound antibody X-ray structure. We also observe that the kinetically dominant antibody paratope conformations are chosen by the bound antigen conformation with the highest probability. Thus, we show that paratope states in solution can improve antibody-antigen docking and structure prediction.
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20
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Fernández-Quintero ML, Kroell KB, Bacher LM, Loeffler JR, Quoika PK, Georges G, Bujotzek A, Kettenberger H, Liedl KR. Germline-Dependent Antibody Paratope States and Pairing Specific V H-V L Interface Dynamics. Front Immunol 2021; 12:675655. [PMID: 34447370 PMCID: PMC8382685 DOI: 10.3389/fimmu.2021.675655] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 06/24/2021] [Indexed: 11/13/2022] Open
Abstract
Antibodies have emerged as one of the fastest growing classes of biotherapeutic proteins. To improve the rational design of antibodies, we investigate the conformational diversity of 16 different germline combinations, which are composed of 4 different kappa light chains paired with 4 different heavy chains. In this study, we systematically show that different heavy and light chain pairings strongly influence the paratope, interdomain interaction patterns and the relative VH-VL interface orientations. We observe changes in conformational diversity and substantial population shifts of the complementarity determining region (CDR) loops, resulting in distinct dominant solution structures and differently favored canonical structures. Additionally, we identify conformational changes in the structural diversity of the CDR-H3 loop upon different heavy and light chain pairings, as well as upon changes in sequence and structure of the neighboring CDR loops, despite having an identical CDR-H3 loop amino acid sequence. These results can also be transferred to all CDR loops and to the relative VH-VL orientation, as certain paratope states favor distinct interface angle distributions. Furthermore, we directly compare the timescales of sidechain rearrangements with the well-described transition kinetics of conformational changes in the backbone of the CDR loops. We show that sidechain flexibilities are strongly affected by distinct heavy and light chain pairings and decipher germline-specific structural features co-determining stability. These findings reveal that all CDR loops are strongly correlated and that distinct heavy and light chain pairings can result in different paratope states in solution, defined by a characteristic combination of CDR loop conformations and VH-VL interface orientations. Thus, these results have broad implications in the field of antibody engineering, as they clearly show the importance of considering paired heavy and light chains to understand the antibody binding site, which is one of the key aspects in the design of therapeutics.
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Affiliation(s)
- Monica L Fernández-Quintero
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Katharina B Kroell
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Lisa M Bacher
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Johannes R Loeffler
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Patrick K Quoika
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Guy Georges
- Roche Pharma Research and Early Development, Large Molecule Research, Roche Innovation Center Munich, Penzberg, Germany
| | - Alexander Bujotzek
- Roche Pharma Research and Early Development, Large Molecule Research, Roche Innovation Center Munich, Penzberg, Germany
| | - Hubert Kettenberger
- Roche Pharma Research and Early Development, Large Molecule Research, Roche Innovation Center Munich, Penzberg, Germany
| | - Klaus R Liedl
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
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21
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Reyes-Ruiz A, Dimitrov JD. How can polyreactive antibodies conquer rapidly evolving viruses? Trends Immunol 2021; 42:654-657. [PMID: 34246558 DOI: 10.1016/j.it.2021.06.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 12/26/2022]
Abstract
Broadly neutralizing antibodies against rapidly evolving viruses (e.g., HIV-1 and influenza virus), often manifest antigen-binding promiscuity. Based on a recent study, we hypothesize on the significance of antibody polyreactivity in neutralization of rapidly evolving viruses. We propose that polyreactivity contributes to toleration of viral variants and shortens the time for generating neutralizing antibodies.
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Affiliation(s)
- Alejandra Reyes-Ruiz
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, 75006 Paris, France
| | - Jordan D Dimitrov
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, 75006 Paris, France.
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22
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Fernández-Quintero ML, Georges G, Varga JM, Liedl KR. Ensembles in solution as a new paradigm for antibody structure prediction and design. MAbs 2021; 13:1923122. [PMID: 34030577 PMCID: PMC8158028 DOI: 10.1080/19420862.2021.1923122] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The rise of antibodies as a promising and rapidly growing class of biotherapeutic proteins has motivated numerous studies to characterize and understand antibody structures. In the past decades, the number of antibody crystal structures increased substantially, which revolutionized the atomistic understanding of antibody functions. Even though numerous static structures are known, various biophysical properties of antibodies (i.e., specificity, hydrophobicity and stability) are governed by their dynamic character. Additionally, the importance of high-quality structures in structure–function relationship studies has substantially increased. These structure–function relationship studies have also created a demand for precise homology models of antibody structures, which allow rational antibody design and engineering when no crystal structure is available. Here, we discuss various aspects and challenges in antibody design and extend the paradigm of describing antibodies with only a single static structure to characterizing them as dynamic ensembles in solution.
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Affiliation(s)
- Monica L Fernández-Quintero
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Guy Georges
- Roche Pharma Research and Early Development, Large Molecule Research, Roche Innovation Center Munich, Penzberg, Germany
| | - Janos M Varga
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Klaus R Liedl
- Department of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
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23
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Schnaack OH, Nourmohammad A. Optimal evolutionary decision-making to store immune memory. eLife 2021; 10:61346. [PMID: 33908347 PMCID: PMC8116052 DOI: 10.7554/elife.61346] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 04/23/2021] [Indexed: 12/25/2022] Open
Abstract
The adaptive immune system provides a diverse set of molecules that can mount specific responses against a multitude of pathogens. Memory is a key feature of adaptive immunity, which allows organisms to respond more readily upon re-infections. However, differentiation of memory cells is still one of the least understood cell fate decisions. Here, we introduce a mathematical framework to characterize optimal strategies to store memory to maximize the utility of immune response over an organism's lifetime. We show that memory production should be actively regulated to balance between affinity and cross-reactivity of immune receptors for an effective protection against evolving pathogens. Moreover, we predict that specificity of memory should depend on the organism's lifespan, and shorter lived organisms with fewer pathogenic encounters should store more cross-reactive memory. Our framework provides a baseline to gauge the efficacy of immune memory in light of an organism's coevolutionary history with pathogens.
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Affiliation(s)
- Oskar H Schnaack
- Max Planck Institute for Dynamics and Self-organization, Göttingen, Germany.,Department of Physics, University of Washington, Seattle, United States
| | - Armita Nourmohammad
- Max Planck Institute for Dynamics and Self-organization, Göttingen, Germany.,Department of Physics, University of Washington, Seattle, United States.,Fred Hutchinson Cancer Research Center, Seattle, United States
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24
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Fernández-Quintero ML, Seidler CA, Quoika PK, Liedl KR. Shark Antibody Variable Domains Rigidify Upon Affinity Maturation-Understanding the Potential of Shark Immunoglobulins as Therapeutics. Front Mol Biosci 2021; 8:639166. [PMID: 33959632 PMCID: PMC8093575 DOI: 10.3389/fmolb.2021.639166] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/17/2021] [Indexed: 12/22/2022] Open
Abstract
Sharks and other cartilaginous fish are the phylogenetically oldest living organisms that have antibodies as part of their adaptive immune system. As part of their humoral adaptive immune response, they produce an immunoglobulin, the so-called immunoglobulin new antigen receptor (IgNAR), a heavy-chain only antibody. The variable domain of an IgNAR, also known as V NAR , binds the antigen as an independent soluble domain. In this study, we structurally and dynamically characterized the affinity maturation mechanism of the germline and somatically matured (PBLA8) V NAR to better understand their function and their applicability as therapeutics. We observed a substantial rigidification upon affinity maturation, which is accompanied by a higher number of contacts, thereby contributing to the decrease in flexibility. Considering the static x-ray structures, the observed rigidification is not obvious, as especially the mutated residues undergo conformational changes during the simulation, resulting in an even stronger network of stabilizing interactions. Additionally, the simulations of the V NAR in complex with the hen egg-white lysozyme show that the V NAR antibodies evidently follow the concept of conformational selection, as the binding-competent state already preexisted even without the presence of the antigen. To have a more detailed description of antibody-antigen recognition, we also present here the binding/unbinding mechanism between the hen egg-white lysozyme and both the germline and matured V NAR s. Upon maturation, we observed a substantial increase in the resulting dissociation-free energy barrier. Furthermore, we were able to kinetically and thermodynamically describe the binding process and did not only identify a two-step binding mechanism, but we also found a strong population shift upon affinity maturation toward the native binding pose.
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Affiliation(s)
| | | | | | - Klaus R. Liedl
- Department of General, Inorganic and Theoretical Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
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25
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Fernández-Quintero ML, Kroell KB, Hofer F, Riccabona JR, Liedl KR. Mutation of Framework Residue H71 Results in Different Antibody Paratope States in Solution. Front Immunol 2021; 12:630034. [PMID: 33737932 PMCID: PMC7960778 DOI: 10.3389/fimmu.2021.630034] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 01/20/2021] [Indexed: 12/13/2022] Open
Abstract
Characterizing and understanding the antibody binding interface have become a pre-requisite for rational antibody design and engineering. The antigen-binding site is formed by six hypervariable loops, known as the complementarity determining regions (CDRs) and by the relative interdomain orientation (VH-VL). Antibody CDR loops with a certain sequence have been thought to be limited to a single static canonical conformation determining their binding properties. However, it has been shown that antibodies exist as ensembles of multiple paratope states, which are defined by a characteristic combination of CDR loop conformations and interdomain orientations. In this study, we thermodynamically and kinetically characterize the prominent role of residue 71H (Chothia nomenclature), which does not only codetermine the canonical conformation of the CDR-H2 loop but also results in changes in conformational diversity and population shifts of the CDR-H1 and CDR-H3 loop. As all CDR loop movements are correlated, conformational rearrangements of the heavy chain CDR loops also induce conformational changes in the CDR-L1, CDR-L2, and CDR-L3 loop. These overall conformational changes of the CDR loops also influence the interface angle distributions, consequentially leading to different paratope states in solution. Thus, the type of residue of 71H, either an alanine or an arginine, not only influences the CDR-H2 loop ensembles, but co-determines the paratope states in solution. Characterization of the functional consequences of mutations of residue 71H on the paratope states and interface orientations has broad implications in the field of antibody engineering.
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Affiliation(s)
- Monica L Fernández-Quintero
- Department of General, Inorganic and Theoretical Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Katharina B Kroell
- Department of General, Inorganic and Theoretical Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Florian Hofer
- Department of General, Inorganic and Theoretical Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Jakob R Riccabona
- Department of General, Inorganic and Theoretical Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Klaus R Liedl
- Department of General, Inorganic and Theoretical Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
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26
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Vajda S, Porter KA, Kozakov D. Progress toward improved understanding of antibody maturation. Curr Opin Struct Biol 2021; 67:226-231. [PMID: 33610066 DOI: 10.1016/j.sbi.2020.11.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 11/25/2020] [Indexed: 11/16/2022]
Abstract
Upon encountering an antigen, antibodies mature through various rounds of somatic mutations, resulting in higher affinities and specificities to the particular antigen. We review recent progress in four areas of antibody maturation studies. (1) Next-generation and single-cell sequencing have revolutionized the analysis of antibody repertoires by dramatically increasing the sequences available to study the state and evolution of the immune system. Computational methods, including machine learning tools, have been developed for reconstituting antibody clonal lineages and for general repertoire analysis. (2) The availability of X-ray structures, thermodynamic and kinetic data, and molecular dynamics simulations provide information on the biophysical mechanisms responsible for improved affinity. (3) In addition to improved binding to a specific antigen, providing affinity-independent diversity and self/nonself discrimination are fundamental functions of the immune system. Recent studies, including X-ray structures, yield improved understanding of both mechanisms. (4) Results from in vivo maturation help to develop methods of in vitro maturation to improve antibody properties for therapeutic applications, frequently combining computational and experimental approaches.
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Affiliation(s)
- Sandor Vajda
- Department of Biomedical Engineering, Boston University, Boston MA 02215, United States.
| | - Kathryn A Porter
- Department of Biomedical Engineering, Boston University, Boston MA 02215, United States
| | - Dima Kozakov
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook NY 11794, United States; Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook NY, 11790, United States.
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27
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Fernández-Quintero ML, Kroell KB, Heiss MC, Loeffler JR, Quoika PK, Waibl F, Bujotzek A, Moessner E, Georges G, Liedl KR. Surprisingly Fast Interface and Elbow Angle Dynamics of Antigen-Binding Fragments. Front Mol Biosci 2020; 7:609088. [PMID: 33330636 PMCID: PMC7732698 DOI: 10.3389/fmolb.2020.609088] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 10/21/2020] [Indexed: 12/14/2022] Open
Abstract
Fab consist of a heavy and light chain and can be subdivided into a variable (V H and V L ) and a constant region (C H 1 and C L ). The variable region contains the complementarity-determining region (CDR), which is formed by six hypervariable loops, shaping the antigen binding site, the paratope. Apart from the CDR loops, both the elbow angle and the relative interdomain orientations of the V H -V L and the C H 1-C L domains influence the shape of the paratope. Thus, characterization of the interface and elbow angle dynamics is essential to antigen specificity. We studied nine antigen-binding fragments (Fab) to investigate the influence of affinity maturation, antibody humanization, and different light-chain types on the interface and elbow angle dynamics. While the CDR loops reveal conformational transitions in the micro-to-millisecond timescale, both the interface and elbow angle dynamics occur on the low nanosecond timescale. Upon affinity maturation, we observe a substantial rigidification of the V H and V L interdomain and elbow-angle flexibility, reflected in a narrower and more distinct distribution. Antibody humanization describes the process of grafting non-human CDR loops onto a representative human framework. As the antibody framework changes upon humanization, we investigated if both the interface and the elbow angle distributions are changed or shifted. The results clearly showed a substantial shift in the relative V H -V L distributions upon antibody humanization, indicating that different frameworks favor distinct interface orientations. Additionally, the interface and elbow angle dynamics of five antibody fragments with different light-chain types are included, because of their strong differences in elbow angles. For these five examples, we clearly see a high variability and flexibility in both interface and elbow angle dynamics, highlighting the fact that Fab interface orientations and elbow angles interconvert between each other in the low nanosecond timescale. Understanding how the relative interdomain orientations and the elbow angle influence antigen specificity, affinity, and stability has broad implications in the field of antibody modeling and engineering.
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Affiliation(s)
- Monica L. Fernández-Quintero
- Center for Molecular Biosciences Innsbruck (CMBI), Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Katharina B. Kroell
- Center for Molecular Biosciences Innsbruck (CMBI), Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Martin C. Heiss
- Center for Molecular Biosciences Innsbruck (CMBI), Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Johannes R. Loeffler
- Center for Molecular Biosciences Innsbruck (CMBI), Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Patrick K. Quoika
- Center for Molecular Biosciences Innsbruck (CMBI), Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Franz Waibl
- Center for Molecular Biosciences Innsbruck (CMBI), Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Alexander Bujotzek
- Roche Pharma Research and Early Development, Large Molecule Research, Roche Innovation Center Munich, Penzberg, Germany
| | - Ekkehard Moessner
- Roche Pharma Research and Early Development, Large Molecular Research, Roche Innovation Center Zurich, Schlieren, Switzerland
| | - Guy Georges
- Roche Pharma Research and Early Development, Large Molecule Research, Roche Innovation Center Munich, Penzberg, Germany
| | - Klaus R. Liedl
- Center for Molecular Biosciences Innsbruck (CMBI), Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
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