Saito Kayo, Muto Tsuyoshi, Tomimori Yoshiaki, Imajo Seiichi, Maruoka Hiroshi, Tanaka Taisaku, Yamashiro Kyoko, Fukuda Yoshiaki
Suntory Biomedical Research Limited, 1-1-1 Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka 618-8503, Japan.
Biochem Biophys Res Commun. 2003 Mar 21;302(4):773-7. doi: 10.1016/s0006-291x(03)00263-8.
The ability to convert angiotensin (Ang) I to Ang II was compared between human alpha-chymase and two mouse beta-chymases, mouse mast cell protease (mMCP)-1 and mMCP-4. Human chymase hydrolyzed Ang I to produce Ang II without further degradation. mMCP-1 similarly generated Ang II from Ang I in a time-dependent manner and the formation of the fragment other than Ang II was marginal. In contrast, mMCP-4 hydrolyzed Ang I at two sites, Tyr(4)-Ile(5) and Phe(8)-His(9), with Ang II formation being tentative. Consistently, mMCP-4 but not human chymase hydrolyzed Ang II and mMCP-1 showed little hydrolytic activity against Ang II. These data suggest that not only human chymase but also mMCP-1 might possess a physiological role in Ang II formation. Our findings also imply that the Ang-converting activity of chymase may not be related to the categorization of chymase into alpha- or beta-type based on their primary structure.
对人α-糜酶与两种小鼠β-糜酶（小鼠肥大细胞蛋白酶（mMCP）-1和mMCP-4）将血管紧张素（Ang）I转化为Ang II的能力进行了比较。人糜酶将Ang I水解生成Ang II，且无进一步降解。mMCP-1同样以时间依赖性方式从Ang I生成Ang II，且除Ang II外的片段形成极少。相比之下，mMCP-4在两个位点Tyr(4)-Ile(5)和Phe(8)-His(9)水解Ang I，Ang II的形成是暂时的。一致的是，mMCP-4而非人糜酶可水解Ang II，且mMCP-1对Ang II几乎没有水解活性。这些数据表明，不仅人糜酶，而且mMCP-1可能在Ang II形成中具有生理作用。我们的研究结果还表明，糜酶的血管紧张素转化活性可能与基于其一级结构将糜酶分类为α型或β型无关。
