Noncompetitive, reversible inhibition of aminoacylase-1 by a series of L-alpha-hydroxyl and L-alpha-fluoro fatty acids: ligand specificity of aspergillus oryzae and porcine kidney enzymes.
L-lactate and L-beta-phenyllactate have been identified in the culture broth of Streptomyces sp. KY-11 as reversible noncompetitive inhibitors of Aspergillus oryzae aminoacylase-1 and porcine kidney aminoacylase I. A series of alpha-hydroxyl acids (DL-R-CH(OH)-COOH, R = Et, n-pro, n-butyl, n-pentyl, n-hexyl) also inhibited the two enzymes in reversible noncompetitive kinetics, and the inhibition potency (-log K(i)) increased with the increased hydrophobicity of the R group. The two eukaryotic enzymes showed distinct preferences to the ligand alpha-alkyl group, and the fungus enzyme was inhibited by L-beta-phenyllactate (R = benzyl) 10(3)-fold more potently than the mammalian enzyme. L-alpha-Fluoro-beta-phenyl-propionate and its D-isomer were used to show that the L-configuration of the alpha-substituent was important for potent inhibition of both the enzymes. The fungus aminoacylase-1 steeply decreased the affinity to alpha-fluoro- and alpha-hydroxy-n-caproate as pH was raised from 7 to 11, whereas the mammalian enzyme retained the affinity to these ligands under alkaline conditions. These results suggest that A. oryzae aminoacylase-1 has an acidic residue that interacts with -OH or -F, while the mammalian enzyme would have a basic residue that recognizes the alpha-substituents.
Tamura
T
T
Department of Bioresources Chemistry, Faculty of Agriculture, Okayama University, 1-1-1, Tsushima-naka, Okayama, 700-8530, Japan.
Oki
Y
Y
Yoshida
A
A
Kuriyama
T
T
Kawakami
H
H
Inoue
H
H
Inagaki
K
K
Tanaka
H
H
D000478:Alkylation; D000581:Amidohydrolases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000818:Animals; D001236:Aspergillus oryzae / Q000201:enzymology*; D002208:Caproates / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D003956:Dialysis; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D005227:Fatty Acids / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D017611:Fluorine Compounds / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D006900:Hydroxylation; D020128:Inhibitory Concentration 50; D007536:Isomerism; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D007773:Lactates / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D015394:Molecular Structure; D010666:Phenylpropionates / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D013302:Streptomyces / Q000737:chemistry; D013379:Substrate Specificity; D013552:Swine; D013816:Thermodynamics; D015032:Zinc / Q000378:metabolism
D002208:Caproates; D004791:Enzyme Inhibitors; D005227:Fatty Acids; D017611:Fluorine Compounds; D007773:Lactates; D010666:Phenylpropionates; C017648:3-phenyllactic acid; D000581:Amidohydrolases; C019672:aminoacylase I; D015032:Zinc