COMPARISON OF CARBOXYPEPTIDASE-A AND THERMOLYSIN - INHIBITION BY PHOSPHONAMIDATES
COMPARISON OF CARBOXYPEPTIDASE-A AND THERMOLYSIN - INHIBITION BY PHOSPHONAMIDATES
复制标题
DOI：
10.1021/ja00224a047
复制
发表时间：
1988-08-03
影响因子：
15
通讯作者：
LIPSCOMB, WN
中科院分区：
文献类型：
--
作者：
CHRISTIANSON, DW;LIPSCOMB, WN
报道了二肽底物Cbz-Gly-L-Phe的过渡态类似物完整的磷酰胺抑制剂N-[[[(benzyloxycarbonyl)amino]methyl]hydroyphosphinyl]-L-phenylalanine(Zgp‘’；Ki=90 nM)与羧基肽酶A(CPA)活性中心的结合。对酶-抑制剂复合体的X射线晶体分析提供了一个分辨率为2.0-.虽然我们之前对该化合物与CPA的研究得到了水解膦的结构，但现在通过最佳的pH调节可以观察到完整的复合体。磷酰胺类和膦酸衍生物类抑制剂的设计都成功地抑制了锌蛋白水解酶的活性，综述了它们与CPA活性部位的结合立体化学以及与之相关的锌内切酶热溶素(TLN)，并根据共同的水解机理进行了考虑。有趣的是，对于CPA和TLN，这些具有P1甘氨酸残基的磷酰胺类抑制剂相对于那些在该位置具有苯丙氨酸侧链的抑制剂显示出异常的结合模式。在目前与CPA的研究中，ZGP‘’的CBZ-Gly部分占据了S1疏水侧链裂隙，而不是结合在主要活性中心沟槽中。ZGP‘’的异常结合模式导致了关于其分类为中间态或过渡态的类似物的问题，至少关于S1亚基的结合。
The binding of the intact phosphonamide inhibitor N-[[[(benzyloxycarbonyl)amino]methyl]hydroyphosphinyl]-L-phenylalanine (ZGP''; Ki = 90 nM), a possible transition-state analogue of the dipeptide substrate Cbz-Gly-L-Phe, to the active site of carboxypeptidase A (CPA) is described, X-ray crystallographic analysis of the enzyme-inhibitor complex provides a well-resolved structure at 2.0-.ANG. resolution. Although our previous study of this compound with CPA yielded the structure of a hydrolyzed phosphonamidate, optimal adjustment of pH now allows the observation of the intact complex. Both phosphonamidate and phosphonate-derived inhibitor designs have realized success toward the inhibition of zinc proteases, and their binding stereochemistry to the active sites of CPA and the related zinc endoprotease thermolysin (TLN) is summarized and considered in light of a common hydrolytic mechanism. Interestingly, for both CPA and TLN these phosphonamidate inhibitors that have P1 glycine residues display anomalous binding modes relative to those inhibitors that have phenylalanine side chains in this position. In the current study with CPA, the CbZ-gly moiety of ZGP'' occupies the S1 hydrophobic side-chain cleft instead of binding in the main active site groove. The anomalous binding mode of ZGP'' leads to questions regarding its classification as an analogue of an intermediate or transition state, at least with regard to binding in the S1 subsite.