title: Tonin, an esteroprotease from rat submaxillary glands.
abstract: Tonin is an enzyme found in the rat submaxillary glands which liberates angiotensin II from angiotensinogen, the Skeggs tetradecapeptide renin substrate, and angiotensin I. Tonin hydrolyzes benzoyl-arginine ethyl ester, benzoyl-arginine methyl ester, tosyl-arginine methyl ester, benzoyl-arginine p-nitroanilide and other small synthetic substrates at an optimum ph of 9.0. Tonin shows, however, a great specificity with respect to angiotensin I. Tonin is inhibited by diisopropyl fluorophosphate and phenylmethylsulfonyl fluoride at high concentrations (greater than 10(-2) M) and by soybean trypsin inhibitor and aprotinin. Tonin is thus an esteroprotease of the class of the serine protease with trypsin- and chymotrypsin-like activity. Tonin belongs to the same family of enzyme as glandular kallikrein and the gamma subunit of the nerve growth factor.
mesh_terms: D000803:Angiotensin I / Q000378:metabolism; D000804:Angiotensin II / Q000378:metabolism; D000806:Angiotensin-Converting Enzyme Inhibitors; D000808:Angiotensinogen / Q000378:metabolism; D000818:Animals; D046911:Macromolecular Substances; D008297:Male; D007703:Peptidyl-Dipeptidase A / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D013363:Submandibular Gland / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D046911:Macromolecular Substances; D000808:Angiotensinogen; D000804:Angiotensin II; D000803:Angiotensin I; D007703:Peptidyl-Dipeptidase A