title: Following single antibody binding to purple membranes in real time.
abstract: Antibody binding to surface antigens in membranes is the primary event in the specific immune defence of vertebrates. Here we used force microscopy to study the dynamics of antibody recognition of mutant purple membranes from Halobacterium salinarum containing a genetically appended anti-Sendai recognition epitope. Ligation of individual anti-Sendai antibodies to their antigenic epitopes was observed over time. Their increase in number within a small selected area revealed an apparent kinetic on-rate. The membrane-bound antibodies showed many different conformations that ranged from globular to V- and Y-like shapes. The maximum distance of two Fab fragments of the same antibody was observed to be approximately 18 nm, indicating an overall strong intrinsic flexibility of the antibody hinge region. Fab fragments of bound anti-Sendai antibodies were allocated to antigenic sites of the purple membrane, allowing the identification and localization of individual recognition epitopes on the surface of purple membranes.
authors.affiliation: Institute for Biophysics, J. Kepler University of Linz, Altenbergerstr. 69, A-4040 Linz, Austria.
authors.forename: Ferry
authors.initials: F
authors.lastname: Kienberger
authors.forename: Harald
authors.initials: H
authors.lastname: Mueller
authors.forename: Vassili
authors.initials: V
authors.lastname: Pastushenko
authors.forename: Peter
authors.initials: P
authors.lastname: Hinterdorfer
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology / Q000648:ultrastructure; D000914:Antibodies, Viral / Q000276:immunology / Q000648:ultrastructure*; D000954:Antigens, Surface / Q000235:genetics / Q000276:immunology; D001666:Binding Sites, Antibody / Q000276:immunology; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000276:immunology; D018604:Epitope Mapping / Q000379:methods*; D019617:Halobacterium salinarum / Q000235:genetics / Q000276:immunology; D007140:Immunoglobulin Fab Fragments / Q000276:immunology / Q000648:ultrastructure; D007700:Kinetics; D018625:Microscopy, Atomic Force; D018717:Purple Membrane / Q000276:immunology*; D029082:Sendai virus / Q000276:immunology; D013995:Time; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000954:Antigens, Surface; D007140:Immunoglobulin Fab Fragments; D014764:Viral Proteins; C064365:L protein, Sendai virus; D012321:DNA-Directed RNA Polymerases