Functional characterization and specific effects of various peptides on enzymatic activity of a DPP-III homologue from goat brain.
The purified dipeptidyl aminopeptidase from goat brain showed several characteristics similar to DPP-III although it possesses a dissimilar molecular weight and different inhibition behavior. The enzyme was found to be inhibited by metallochelators and thiol inhibitors which could be reversed by introducing metals and thiols, respectively. The enzyme activity is also significantly affected by DMSO and ethanol. It was found to be highly sensitive to even very low concentration of urea. The inhibitory potency of several dipeptides and bioactive peptides on this enzyme was investigated to characterize its active site. The highest potency was observed for the dipeptides having aromatic and bulky side chains such as Phe-Met, Leu-Arg, Met-Arg, Trp-Met and Leu-Trp.
Dhanda
Suman
S
Department of Biochemistry, Kurukshetra University, Kurukshetra, India. dhandasuman@rediffmail.com
Singh
Hari
H
Singh
Jasbir
J
Singh
Tej P
TP
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002413:Cations, Divalent / Q000737:chemistry; D004121:Dimethyl Sulfoxide; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000037:antagonists & inhibitors / Q000145:classification / Q000378:metabolism*; D004228:Dithionitrobenzoic Acid / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D000431:Ethanol; D006041:Goats; D008670:Metals / Q000737:chemistry; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology*; D010618:Phenanthrolines / Q000494:pharmacology; D011480:Protease Inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D013379:Substrate Specificity; D013438:Sulfhydryl Compounds; D014508:Urea
D002413:Cations, Divalent; D008670:Metals; D010455:Peptides; D010618:Phenanthrolines; D011480:Protease Inhibitors; D013438:Sulfhydryl Compounds; D000431:Ethanol; D014508:Urea; D004228:Dithionitrobenzoic Acid; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; C100151:dipeptidyl peptidase II; C025205:1,10-phenanthroline; D004121:Dimethyl Sulfoxide