Acidic tripeptidyl aminopeptidase in rat liver tritosomes: partial purification and determination of its primary substrate specificity.
We have found the enrichment in rat liver tritosomes of an enzyme which hydrolyzed the synthetic substrate, Ala-Ala-Phe-pNA, under acidic conditions. The enzyme cleaved the substrate in an exopeptidolytic manner, releasing Ala-Ala-Phe. The enzyme was solubilized from tritosomes and partially purified. Beside Ala-Ala-Phe-pNA, the obtained enzyme was shown to cleave angiotensin III (Arg-Val-Tyr-Ile-His-Pro-Phe) and des-1Tyr-dynorphin A 1-8 (Gly-Gly-Phe-Leu-Arg-Arg-Ile) with tripeptide units. The results obtained suggested that the enzyme preferred an aromatic amino acid at the third position of a substrate peptide.
Watanabe
Y
Y
Department of Clinical Biochemistry, Hokkaido Institute of Pharmaceutical Sciences, Japan.
Kumagai
Y
Y
Fujimoto
Y
Y
D000143:Acids; D000595:Amino Acid Sequence; D000626:Aminopeptidases; D000818:Animals; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; D010450:Endopeptidases / Q000187:drug effects / Q000302:isolation & purification* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006868:Hydrolysis; D008099:Liver / Q000201:enzymology*; D008297:Male; D008969:Molecular Sequence Data; D015388:Organelles / Q000201:enzymology*; D010446:Peptide Fragments / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D013379:Substrate Specificity
D000143:Acids; D004791:Enzyme Inhibitors; D010446:Peptide Fragments; D010450:Endopeptidases; D000626:Aminopeptidases; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases