Preparation and Application of Anti-idiotypic Antibody against Anti-gibberellin A₄ Antibody

Abstract

  A monoclonal anti-idiotypic antibody was raised against anti-gibberellin A₄ (GA₄) antibody, which recognizes biologically active gibberellins such as GA₁ and GA₄ specifically. Amino acid sequences of variable regions of both anti-GA₄ and anti-idiotypic antibodies were analyzed. By using the property of the anti-idiotypic antibody to compete with GA_1/4 in binding to the anti-GA₄ antibody, we successfully applied the anti-idiotypic antibody to ELISA as a tracer for measuring GA_1/4. The single-chain Fv (scFv) gene of the anti-idiotypic antibody was constructed, and scFv expressed in E. coli showed binding activity to anti-GA₄ antibody. These results suggest the possible application of anti-idiotypic antibody as a handy and stable source of an enzymatic tracer for ELISA by production of fusion protein of the scFv and an appropriate enzyme.