Direct affinity measurement of human IgG1 binding multimeric antigens

Abstract

Herein is reported a method for determining the binding affinity of the binding sites of a bivalent full length antibody of the human IgG1 subclass to a homo-multimeric antigen comprising the steps of i) incubating a mixture comprising the antibody and a polypeptide that is derived from lysine-gingipain of Porphyromonas gingivalis at a pH of from pH 7.5 to pH 8.5, in the presence of a reducing agent, at a temperature of from 30° C. to 42° C., for time of from 10 min. to 240 min. to cleave the antibody into Fabs and Fc-region, and ii) determining the binding affinity of the Fabs of the antibody for its antigen using a surface plasmon resonance method by directly applying the incubated reaction mixture obtained in the previous step in the surface plasmon resonance method and therewith determining the binding affinity of the binding sites of the bivalent full length antibody of the human IgG1 subclass.

Dependencies are inferred from the claim text.