Association constants of hybridoma antibodies specific for α(1 → 6) linked dextran determined by affinity electrophoresis

Abstract

Binding constants of monomers of seven BALB/c IgM, four BALB/c IgA, and one C57BL/6 IgA anti- α (1 → 6) dextran hybridoma antibodies with dextran B512 and with isomaltoheptaose were determined by affinity electrophoresis. Binding constants to dextran range from 1.52 × 10 5 to 4.43 × 10 5 ml/g for the five IgA monomers and from 1.70 × 10 3 to 6.10 × 10 4 ml/g for the seven IgM monomers. Antibody monomers containing both specific and nonspecific (derived from the myeloma cell that was used to generate the hybridomas) light chains are shown to have association constants with dextran 6 to 30-fold lower than monomers containing only specific light chain, suggesting that the association of specific heavy chain with nonspecific light chain does not result in an anti-dextran combining site. Binding constants with isomaltoheptaose range from 1.45 × 10 4 to 7.01 × 10 4/M for the IgA proteins and from 6.46 × 10 3 to 7.70 × 10 4/M for the IgM proteins. The binding constants with dextran and with isomaltoheptaose, and the electrophoretic, immunochemical and idiotypic characteristics of the hybridoma proteins are discussed.