L-ornithine-induced inactivation of mammalian ornithine decarboxylase in vitro.
Partially purified ornithine decarboxylase, isolated from the liver of thioacetamide-treated rats, is stable in the absence of added low-molecular-mass thiols or other reducing agents. However, under these conditions, the enzyme is rapidly inactivated upon incubation with L-ornithine or L-2-methylornithine. The inactivation process follows first-order kinetics, and saturation kinetics are observed. Rapid recovery of activity is observed after subsequent addition of dithiothreitol. As distinct from L-ornithine, D-ornithine, putrescine, spermidine, or spermine do not produce inactivation of ornithine decarboxylase. Very similar results are obtained with pure ornithine decarboxylase isolated from androgen-stimulated mouse kidney, stabilized with a rat liver extract.
D000818:Animals; D004229:Dithiothreitol / Q000494:pharmacology; D066298:In Vitro Techniques; D007668:Kidney / Q000201:enzymology; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D008297:Male; D051379:Mice; D009952:Ornithine / Q000494:pharmacology*; D065108:Ornithine Decarboxylase Inhibitors; D051381:Rats; D011919:Rats, Inbred Strains
D065108:Ornithine Decarboxylase Inhibitors; D009952:Ornithine; D004229:Dithiothreitol