Production and characterization of monoclonal anti-idiotypic antibodyexhibiting a catalytic activity similar to carboxypeptidase A

摘要

A new approach for producing catalytic antiidiotypic antibody was developed. A monoclonal anti-idiotypic antibody which was induced against carboxypeptidase A (CPA) showed the catalytic activity similar to the original antigen. The activity of the catalytic antibody was in investigated. Rabbits were immunized by bovine pancreas carboxypeptidase A. The antiserum was purified and used as antigen to immunize BALB/c mice to induce monoclonal anti-idiotypic antibodies. Screened for enzymatic activities, the monoclonal antibody 32C3 showed esterase activity. The hydrolysis of hippuryl-DL-phenyllactic acid by McAb 32C3 followed the enzymatic kinetics. In our experimental system, K-cat value was 0.0123 min(-1) and K(m)( )was 0.04 M. The acceleration rate was 1750 times compared to the rate of self-hydrolysis of the substrate.This hydrolysis reaction can be competitively inhibited by hydrocinnamic acid. This method could be effective to obtain catalytic antibodies with the characters close to natural enzymes.