Characterization of a monoclonal antibody to ligandin

A monoclonal antibody has been produced in the mouse system using purified rat liver ligandin as antigen. The antibody is of the immunoglobulin M class and appears to be specific for the Ya subunit of lowest molecular weight which comprises the isoenzymes of glutathione S-transferases in rat liver. Of the series of glutathione S-transferases, the antibody cross-reacted with purified ligandin (YaYa) and, in ion-exchange separations of isoenzymes, gave positive Western blots with fractions containing glutathione S-transferases B and a combination of D and E. Interactions of the immunoglobulin M antibody and the antigen were demonstrated using 125I-ligandin (YaYa) and physical separations in gel filtration experiments. The antibody did not inhibit the glutathione S-transferase activity of ligandin (YaYa) but rather increased the catalytic activity in a dose-dependent fashion up to a molar ratio of antiligandin:ligandin of 24.