title: Affinity labeling of purified ornithine decarboxylase by alpha-difluoromethylornithine.
abstract: Ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) purified from rat liver was affinity-labeled by alpha-[5-14C]difluoromethylornithine. On analysis by SDS-polyacrylamide gel electrophoresis, the radioactivity migrated as a single major peak that coincided with a single protein band of Mr 50,000. Calculation from bound radioactivity indicated that ornithine decarboxylase has two active sites, one for each subunit, and that pure enzyme should have a specific activity of about 1.4 x 10(6) nmol CO2/h per mg protein.
mesh_terms: D000345:Affinity Labels; D000818:Animals; D002262:Carboxy-Lyases / Q000037:antagonists & inhibitors*; D000518:Eflornithine; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D008970:Molecular Weight; D009952:Ornithine / Q000031:analogs & derivatives* / Q000494:pharmacology; D065108:Ornithine Decarboxylase Inhibitors; D051381:Rats
chemical_list: D000345:Affinity Labels; D065108:Ornithine Decarboxylase Inhibitors; D009952:Ornithine; D002262:Carboxy-Lyases; D000518:Eflornithine