The X-ray structure of carboxypeptidase A inhibited by a thiirane mechanism-based inhibitor.
The X-ray structure of carboxypeptidase A inhibited by a thiirane mechanism-based inhibitor.
复制标题
基于硫杂丙环机制的抑制剂抑制羧肽酶 A 的 X 射线结构。
DOI：
10.1111/j.1747-0285.2009.00907.x
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发表时间：
2010
影响因子：
3
通讯作者：
Mobashery,Shahriar
中科院分区：
文献类型：
--
作者：
Fernandez,Daniel;Testero,Sebastian;Vendrell,Josep;Aviles,FrancescX;Mobashery,Shahriar
羧肽酶 A 是一种锌依赖性水解酶，由基于机制的硫杂丙环灭活剂 2-苄基-3,4-环硫丁酸共价修饰，其三维 X 射线晶体结构已解析至 1.38 Å 分辨率。抑制剂的硫杂丙环部分与活性位点锌离子的相互作用促进其对 Glu-270 的共价修饰，并伴随着硫杂丙环的打开。高分辨率的晶体结构测定使得谷氨酸侧链的共价酯键清晰可见。抑制剂新生成的硫醇以单齿方式与催化锌离子结合，引起锌离子几何结构和配位的变化，而其苄基适合酶的 S1' 特异性口袋。抑制剂分子在一侧参与酯键连接和另一侧参与锌配位的碳原子位置发生扭曲。这种特殊类型的基于硫杂丙环的金属蛋白酶抑制剂首次以高分辨率与目标蛋白酶复合物进行分析，可用作锌依赖性蛋白酶的通用模型。
The three‐dimensional X‐ray crystal structure of carboxypeptidase A, a zinc‐dependent hydrolase, covalently modified by a mechanism‐based thiirane inactivator, 2‐benzyl‐3,4‐epithiobutanoic acid, has been solved to 1.38 Å resolution. The interaction of the thiirane moiety of the inhibitor with the active site zinc ion promotes its covalent modification of Glu‐270 with the attendant opening of the thiirane ring. The crystal structure determination at high resolution allowed for the clear visualization of the covalent ester bond to the glutamate side chain. The newly generated thiol from the inhibitor binds to the catalytic zinc ion in a monodentate manner, inducing a change in the zinc ion geometry and coordination, while its benzyl group fits into the S1’ specificity pocket of the enzyme. The inhibitor molecule is distorted at the position of the carbon atom that is involved in the ester bond linkage on one side and the zinc coordination on the other. This particular type of thiirane‐based metalloprotease inhibitor is for the first time analyzed in complex to the target protease at high resolution and may be used as a general model for zinc‐dependent proteases.