title: Dipeptidyl-aminopeptidase III of rat brain. Selective affinity for enkephalin and angiotensin.
abstract: The cytosolic dipeptidyl-aminopeptidase III (EC 3.4.14.4) from rat brain was partially purified using Arg-Arg-4-methoxy-beta-naphthylamide as a substrate. It was completely separated from aminopeptidase B on DEAE-Sephacel ion exchange chromatography. Similar to bovine pituitary dipeptidyl-aminopeptidase III, it has a pH optimum of 9, prefers Arg-Arg-4-methoxy-beta-naphthylamide as a substrate, and catalyzes the sequential release of dipeptides from the NH2 terminus of peptide substrates provided they are not smaller than a tetrapeptide. Among numerous biologically active peptides tested, angiotensins and enkephalins were the most preferred substrates with micromolar affinities, suggesting that dipeptidyl-aminopeptidase III may play a physiologic role in regulating enkephalin and/or angiotensin disposition.
mesh_terms: D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002851:Chromatography, High Pressure Liquid; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D004743:Enkephalin, Leucine / Q000378:metabolism; D004745:Enkephalins / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D010446:Peptide Fragments / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D013379:Substrate Specificity
chemical_list: D004745:Enkephalins; D010446:Peptide Fragments; D000804:Angiotensin II; D004743:Enkephalin, Leucine; D010450:Endopeptidases; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases