Angiotensin I-converting enzyme inhibitors derived from an enzymatic hydrolysate of casein. Part IV Studies on the active site and antihypertensive activity of angiotensin I-converting enzyme inhibitors derived from casein.

• DOI: 10.1271/bbb1961.51.1581
• Publication Date: 2011-07-13T06:02:44Z
• Authors: Susumu MARUYAMA; Hajime MITACHI; Hideoki TANAKA; Noboru TOMIZUKA; Hideo SUZUKI
• Keywords: Tripeptide

The fragment-peptides of angiotensin I-converting enzyme inhibitors (CEI12, CEI5 and CEIβ7) derived from an enzymatic hydrolysate casein were synthesized. Val-Ala-Pro, the C-terminal tripeptide (Phe-Phe-Val-Ala-Pro), exhibited more potent inhibitory activity (I50=2.0μM) than (I50=6.0μM). However, D-Val-Ala-Pro showed lower (I50=550μM). Val-Ala-Pro may be important for CEI5. heptapeptide CEI12 (Phe-Phe-Val-Ala-Pro-Phe-Pro-Glu-Val-Phe-Gly-Lys) short fragments CEIβ7 (Ala-Val-Pro-Tyr-Pro-Gln-Arg) activities full-length peptides. Also, antihypertensive was investigated. CEI12, intravenously administered to anesthetized rats at 14.2mg/kg, antagonized rats' pressor response I.