Lack of species specificity of antibody to an enzyme.

Antibodies to crystalline bovine hepatic L-glutamic dehydrogenase were induced in rabbits. These antibodies inhibited the bovine glutamic dehydrogenase used as antigen, and also inhibited glutamic dehydrogenases from rat, rabbit, human, pigeon, and frog livers, as well as frog renal and muscle glutamic dehydrogenase. The antibody did not inhibit yeast glutamic dehydrogenase which differs from the animal enzymes in cofactor requirement. The kinetic characteristics of the inhibition of the bovine glutamic dehydrogenase indicate mixed competitive and non-competitive inhibition, suggesting reaction with multiple antigenic sites; the data indicate competitive inhibition of the enzyme from other species, suggesting reaction with the catalytic site.