title: [Physiological importance of microvilli-bound leucinarylamidase in the final digestion of proteins. 4. Inhibition of microvilli-bound leucinarylamidase by free amino acids].
abstract: The microvilli-bound leucine arylamidase is inhibited by certain amino acids. An inhibitory action is exerted by the branched-chain amino acids L-leucine and L-isoleucine and by the aromatic amino acids L-tyrosine and L-phenylalanine with Ki values of 4--6 . 10(-3) M. L-methionine (Ki = 2.5 . 10(-3) M) and its higher homologue L-ethionine (Ki = 1.1 . 10(-3) M) are the most potent inhibitors. Derivatization of L-methionine on the sulphur or the nitrogen atom or the carboxyl group prevents the inhibitory effect just as the D-isomer.
mesh_terms: D000596:Amino Acids / Q000494:pharmacology*; D002462:Cell Membrane / Q000201:enzymology*; D007422:Intestines / Q000648:ultrastructure; D007700:Kinetics; D007931:Leucyl Aminopeptidase / Q000037:antagonists & inhibitors*; D008871:Microvilli / Q000201:enzymology*; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D000596:Amino Acids; D011506:Proteins; D007931:Leucyl Aminopeptidase
vernacular_title: Untersuchungen zur physiologischen Bedeutung der bürstensaumgebundenen Leucinarylamidase für die Endverdauung von Proteinen. 4. Mitt. Die Hemmung der bürstensaumgebundenen Leucinarylamidase durch freier Aminosäuren.