title: [Inhibition of aminopeptidase activity of rat small intestine by the tripeptide H-Thr-(O-tert. butyl)-Phe-Pro-OH].
abstract: The hydrolysis of L-leucine-beta-naphthylamide and L-leucinamide by leucinaminopeptidase (E.C. 3.4.11.1) from bovine eye lens is inhibited by H-Thr (O-tert. butyl)-Phe-Pro-OH. The inhibitor constants are Ki = 1.5 . 10(-5) M and 0.8 . 10(-5) M, respectively. Both brush border peptidases, leucinarylamidase (E.C. 3.4.11.2) AND TRIPEPTIDASE (E.C. 3.4.11.4), are inhibited to a smaller extent (Ki = 0.8 . 10(-3) M). Mn++-ions activate the cytosolic leucinaminopeptidase but not the hydrolysis of leucinamide by the brush border arylamidase. The inhibition of the cytosolic leucinamidase by the peptide (Ki = 3.5 . 10(-4)) is twice as that of the brush border arylamidase.
mesh_terms: D000626:Aminopeptidases / Q000037:antagonists & inhibitors*; D000818:Animals; D003600:Cytosol / Q000201:enzymology; D007421:Intestine, Small / Q000201:enzymology*; D007700:Kinetics; D007931:Leucyl Aminopeptidase / Q000037:antagonists & inhibitors; D008871:Microvilli / Q000201:enzymology; D009842:Oligopeptides / Q000494:pharmacology*; D011480:Protease Inhibitors; D051381:Rats
chemical_list: D009842:Oligopeptides; D011480:Protease Inhibitors; D000626:Aminopeptidases; D007931:Leucyl Aminopeptidase
vernacular_title: Hemmung der aminopeptidatischen Aktivitäten des Rattendünndarmes durch das Tripeptid H-Thr-(O-tert. Butyl)-Phe-Pro-OH.