title: ATP and other purine nucleotides stimulate the inactivation of ornithine transcarbamylase by broken lysosomes.
abstract: Ornithine transcarbamylase (OTC) is very stable in rat liver homogenates, or mitochondria. However, pure OTC from rat or beef liver is inactivated by broken lysosomes. ATP and a number of purine nucleotides, particularly epsilon-ATP, stimulate the inactivation of OTC by broken lysosomes. Inactivation of OTC by trypsin and elastase is also stimulated by epsilon-ATP. Carbamoyl phosphate protects OTC against proteolytic attack by elastase or by broken lysosomes. Thus, environmental factors, e.g., ATP and carbamoyl phosphate, appear to influence OTC stability to proteases.
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D002221:Carbamyl Phosphate / Q000494:pharmacology; D002417:Cattle; D008247:Lysosomes / Q000201:enzymology*; D008297:Male; D008930:Mitochondria, Liver / Q000201:enzymology; D009954:Ornithine Carbamoyltransferase / Q000037:antagonists & inhibitors*; D010196:Pancreatic Elastase / Q000378:metabolism; D011685:Purine Nucleotides / Q000494:pharmacology; D051381:Rats; D014357:Trypsin / Q000378:metabolism
chemical_list: D011685:Purine Nucleotides; D002221:Carbamyl Phosphate; D000255:Adenosine Triphosphate; D009954:Ornithine Carbamoyltransferase; D010196:Pancreatic Elastase; D014357:Trypsin