First order dissociation rates between a subpopulation of high affinity rabbit anti-fluorescyl IgG antibody and homologous ligand

Abstract

The first order dissociation rates of liganded subpopulations of purified hyperimmune rabbit antifluorescyl IgG antibodies were determined using the method of Green (1963). The dissociation of radiolabeled fluorescyl ligands was measured in the presence of excess unlabeled homologous hapten. Results with three different antibody preparations indicated dissociation rates of 1.3 × 10[su−3, 2.4 × 10−4 and 2.2 × 10−6 sec−1 for the liganded subpopulations. Assuming an association rate of 4.6 × 108M−1 sec−1 (Levison et al., 1971), average equilibrium constants ranging from 3.1 × 1011M−1 to 2.1 × 1014M−1 were calculated. These values are among the highest reported for antibody-hapten interactions. © 1980, All rights reserved.