title: Structure of the major antigenic loop of foot-and-mouth disease virus complexed with a neutralizing antibody: direct involvement of the Arg-Gly-Asp motif in the interaction.
abstract: The crystal structure of a synthetic peptide representing the major antigenic loop of foot-and-mouth disease virus (FMDV), complexed with the Fab fragment of a neutralizing monoclonal antibody raised against the virus, has been determined at 2.8 A resolution. The peptide shows a high degree of internal structure with a nearly cyclic conformation. The conserved Arg-Gly-Asp motif, involved in the viral attachment of aphtoviruses to cells, participates directly in the interaction with several complementarity determining regions of the antibody molecule. The Arg-Gly-Asp triplet shows the same open turn conformation found in the reduced form of FMDV of another serotype and also in integrin binding proteins. The observed interactions provide a molecular interpretation of the amino acid replacements observed to occur in mutants resistant to neutralization by this antibody. The structure also suggests a number of restrictions to variation within the epitope which are imposed to keep the Arg-Gly-Asp motif in its functional conformation.
authors.affiliation: Departament d'Enginyeria Química, Universitat Politécnica de Catalunya, Barcelona, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Verdaguer
authors.forename: M G
authors.initials: MG
authors.lastname: Mateu
authors.forename: D
authors.initials: D
authors.lastname: Andreu
authors.forename: E
authors.initials: E
authors.lastname: Giralt
authors.forename: E
authors.initials: E
authors.lastname: Domingo
authors.forename: I
authors.initials: I
authors.lastname: Fita
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology; D000914:Antibodies, Viral / Q000737:chemistry* / Q000276:immunology; D000936:Antigen-Antibody Complex / Q000737:chemistry* / Q000276:immunology; D005537:Aphthovirus / Q000276:immunology*; D018360:Crystallography, X-Ray; D000939:Epitopes / Q000737:chemistry* / Q000276:immunology; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000276:immunology; D011485:Protein Binding
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000936:Antigen-Antibody Complex; D000939:Epitopes; D007140:Immunoglobulin Fab Fragments; D009842:Oligopeptides; C047981:arginyl-glycyl-aspartic acid