猴脑来源的血管紧张素转换酶对新京都啡肽（苏氨酸-丝氨酸-赖氨酸-酪氨酸-精氨酸）和[甲硫氨酸]脑啡肽-精氨酸6-苯丙氨酸7的水解作用。

Hydrolysis of neo-kyotorphin (Thr-Ser-Lys-Tyr-Arg) and [Met]enkephalin-Arg6-Phe7 by angiotensin-converting enzyme from monkey brain.

作者信息

Kase R, Sekine R, Katayama T, Takagi H, Hazato T

出版信息

Biochem Pharmacol. 1986 Dec 15;35(24):4499-503. doi: 10.1016/0006-2952(86)90770-7.

Abstract

Angiotensin-converting enzyme (ACE; dipeptidyl carboxypeptidase, EC 3.4.15.1) from monkey brain was partially purified 274-fold with 4.5% yield. The optimum pH of the enzyme was 8.2, and its Km was 3.3 mM, with hippuryl-His-Leu as the substrate in 300 mM NaCl. Its molecular weight (Mr) was estimated to be approximately 260,000 by gel filtration on Sephadex G-200. On high-performance liquid chromatographic analysis, ACE hydrolyzed neo-kyotorphin Thr-Ser-Lys-Tyr-Arg) with liberation of kyotorphin (Tyr-Arg), the [Met]enkephalin releaser. ACE also converted [Met]enkephalin-Arg6-Phe7 to [Met]enkephalin; then the enzyme slowly hydrolyzed the resulting [Met]enkephalin. The Km values of the enzyme for neo-kyotorphin and [Met]enkephalin-Arg6-Phe7 were 0.58 and 0.30 mM respectively. Thus, brain ACE may have a role in the formation of kyotorphin and [Met]enkephalin from their precursors but has little part in [Met]enkephalin degrading processes.

摘要

从猴脑中部分纯化血管紧张素转换酶（ACE；二肽基羧肽酶，EC 3.4.15.1），纯化倍数为274倍，产率为4.5%。该酶的最适pH为8.2，以马尿酰 - 组氨酸 - 亮氨酸为底物，在300 mM氯化钠中其Km为3.3 mM。通过在Sephadex G - 200上进行凝胶过滤，估计其分子量（Mr）约为260,000。在高效液相色谱分析中，ACE水解新京都啡肽（苏氨酸 - 丝氨酸 - 赖氨酸 - 酪氨酸 - 精氨酸），释放出京都啡肽（酪氨酸 - 精氨酸），即甲硫氨酸脑啡肽释放剂。ACE还将甲硫氨酸脑啡肽 - 精氨酸6 - 苯丙氨酸7转化为甲硫氨酸脑啡肽；然后该酶缓慢水解生成的甲硫氨酸脑啡肽。该酶对新京都啡肽和甲硫氨酸脑啡肽 - 精氨酸6 - 苯丙氨酸7的Km值分别为0.58和0.30 mM。因此，脑ACE可能在由其前体形成京都啡肽和甲硫氨酸脑啡肽的过程中起作用，但在甲硫氨酸脑啡肽的降解过程中作用不大。