Purification of NADP-dependent glutamate dehydrogenase from Pseudomonas aeruginosa and immunochemical characterization of its in vivo inactivation.

The 'high ammonia pathway' enzyme glutamate dehydrogenase (NADP+) is inactivated in cells of Pseudomonas aeruginosa when the stationary phase of growth is reached. Purified glutamate dehydrogenase (NADP+) appeared to be a protein composed of six identical subunits with a molecular weight of 54 000. With antibodies raised against purified enzyme it was found that glutamate dehydrogenase (NADP+) inactivation is accompanied by a parallel decrease in immunologically reactive material. This suggests that glutamate dehydrogenase (NADP+) inactivation is caused or followed by rapid proteolysis.