Action of brain cathepsin B, cathepsin D, and high-molecular-weight aspartic proteinase on angiotensins I and II.
The action of three previously isolated electrophoretically homogeneous brain proteinases--cathepsin B (EC 3.4.22.1), cathepsin D (EC 3.4.23.5), and high-molecular-weight aspartic proteinase (Mr = 90K; EC 3.4.23.-)--on human angiotensins I and II has been investigated. The products of enzymatic hydrolysis have been identified by thin-layer chromatography on Silufol plates using authentic standards and by N-terminal amino acid residue analysis using a dansyl chloride method. Cathepsin D and high-molecular-weight aspartic proteinase did not split angiotensin I or angiotensin II. Cathepsin B hydrolyzed angiotensin I via a dipeptidyl carboxypeptidase mechanism removing His-Leu to form angiotensin II, and it degraded angiotensin II as an endopeptidase at the Val3-Tyr4 bond. Cathepsin B did not split off His-Leu from Z-Phe-His-Leu. Brain cathepsin B may have a role in the generation and degradation of angiotensin II in physiological conditions.
D000803:Angiotensin I / Q000378:metabolism; D000804:Angiotensin II / Q000378:metabolism; D000809:Angiotensins / Q000378:metabolism*; D000818:Animals; D016282:Aspartic Acid Endopeptidases; D002384:Catalysis; D002401:Cathepsin B; D002402:Cathepsin D / Q000378:metabolism; D002403:Cathepsins / Q000378:metabolism*; D002417:Cattle; D010450:Endopeptidases / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D066298:In Vitro Techniques
D000809:Angiotensins; D000804:Angiotensin II; D000803:Angiotensin I; D002403:Cathepsins; D010450:Endopeptidases; D002401:Cathepsin B; D016282:Aspartic Acid Endopeptidases; D002402:Cathepsin D