Chaturvedi D, Huelar E, Gunthorpe M, Gofman M, Krapf D S, Apostol E, Lewis W S
Diagnostic Products Corporation, Los Angeles, CA 90045.
Pept Res. 1993 Nov-Dec;6(6):308-12.
A series of peptide analogs and fragments of bradykinin were designed and synthesized on solid supports using Boc and Fmoc strategies, and on polyethylene pins using Fmoc strategy. The peptides were purified, characterized and tested for their inhibitory effects on angiotensin-converting enzyme. The inhibition of the converting enzyme. The inhibition of the enzyme was measured spectrophotometrically using Furylacryloyl-Phe-Gly-Gly as the substrate. Apparent Ki's were determined for the substrates, which exhibited significant inhibition in the initial screening assay using 10 microM of the peptide inhibitor. Short peptides corresponding to the carboxyl terminus of bradykinin were found to be poor inhibitors of angiotensin-converting enzyme. However, bradykinin-like peptides with modifications at their amino terminus are effective inhibitors. The best inhibitor found in this study, Ala2,6-des-Pro3-bradykinin, has an apparent Ki of 30.2 nM, compared to an apparent Ki of 94 nM for des-Pro3-bradykinin, which was reported to be a better inhibitor of angiotensin-converting enzyme than captopril.
采用Boc和Fmoc策略在固相载体上，以及采用Fmoc策略在聚乙烯针上设计并合成了一系列缓激肽的肽类似物和片段。对这些肽进行了纯化、表征，并测试了它们对血管紧张素转换酶的抑制作用。使用呋喃丙烯酰 - 苯丙氨酸 - 甘氨酸 - 甘氨酸作为底物，通过分光光度法测定酶的抑制作用。确定了底物的表观抑制常数（Ki），在使用10微摩尔肽抑制剂的初始筛选试验中，这些底物表现出显著的抑制作用。发现对应于缓激肽羧基末端的短肽是血管紧张素转换酶的弱抑制剂。然而，在其氨基末端有修饰的类缓激肽是有效的抑制剂。在本研究中发现的最佳抑制剂Ala2,6 - 去 - Pro3 - 缓激肽的表观Ki为30.2纳摩尔，相比之下，去 - Pro3 - 缓激肽的表观Ki为94纳摩尔，据报道去 - Pro3 - 缓激肽是比卡托普利更好的血管紧张素转换酶抑制剂。
