title: Real-time measurement of spontaneous antigen-antibody dissociation.
abstract: We report observations in real time of thermally driven adhesion and dissociation between a monoclonal IgE antibody and its specific antigen N-epsilon-2,4-dinitrophenyl-L-lysine. Both molecules were attached to the surfaces of different polystyrene microspheres trapped by optical tweezers. Monitoring spontaneous successive attachment and detachment events allowed a direct determination of the reaction-limited detachment rate k(off) for a single bond and also for multiple bonds. We observed both positive and negative cooperativity between multiple bonds depending on whether the antigen was linked to the microsphere with or without a tether, respectively.
mesh_terms: D000937:Antigen-Antibody Reactions; D055592:Biophysical Phenomena; D001703:Biophysics; D002448:Cell Adhesion; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D006241:Haptens / Q000737:chemistry; D007073:Immunoglobulin E / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D008239:Lysine / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000378:metabolism; D013997:Time Factors
chemical_list: D006241:Haptens; C007493:epsilon-dinitrophenyllysine; D007073:Immunoglobulin E; D008239:Lysine