Inhibition and affinity chromatography of human serum angiotensin converting enzyme with cysteinyl-proline derivatives.
Inhibition and affinity chromatography of human serum angiotensin converting enzyme with cysteinyl-proline derivatives.
复制标题
半胱氨酰脯氨酸衍生物对人血清血管紧张素转化酶的抑制和亲和层析。
DOI：
10.1016/0003-9861(81)90071-0
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发表时间：
1981
影响因子：
3.9
通讯作者：
Wilson,IB
中科院分区：
文献类型：
--
作者：
Harris,RB;Ohlsson,JT;Wilson,IB
合成了几种二肽的结构衍生物，l（和d）-半胱氨酰-l-脯氨酸，并显示出对人血清血管紧张素I转换酶的非常有效的竞争性和非竞争性抑制剂。只有当半胱氨酸的巯基被苄基、三苯甲基或苄氧羰基保护基团封闭时，二肽才是非竞争性抑制剂。具有游离巯基的化合物是竞争性抑制剂，Ki值在10− 8 m范围内。我们最有效的抑制剂d-Cys-l-Pro（k1= 0.0055 μM）比l-Cys-l-Pro强一个数量级，与Cushmanet al.的发现一致。(1977，Biochemistry 16，5484），如果构型为d，-CH 3基团取代改善结合，但如果构型为l，则减少结合。锌和钙离子释放抑制的一些非竞争性，但只有一个，竞争性抑制剂。非竞争性抑制剂，l-半胱氨酰（苄基）-l-脯氨酸，和竞争性抑制剂，l-半胱氨酰-l-脯氨酸，被用作亲和配体，以获得接近同质（25单位/毫克）的酶从人血浆。如果转化酶的活性位点是一个延伸的线性沟槽，则观察到具有游离巯基的化合物是竞争性抑制剂，而巯基被封闭的化合物是非竞争性抑制剂可以合理化。
Several structural derivatives of the dipeptide,l(andd)-cysteinyl-l-proline were synthesized and shown to be very potent competitive and noncompetitive inhibitors of human serum angiotensin I-converting enzyme. Only if the sulfhydryl group of the cysteine was blocked with benzyl, trityl, or benzyloxycarbonyl protecting groups, was the dipeptide a noncompetitive inhibitor. Compounds with free sulfhydryl groups were competitive inhibitors withKivalues in the 10−8mrange.d-Cys-l-Pro, our most potent inhibitor (k1= 0.0055 μM), was an order of magnitude more potent thanl-Cys-l-Pro consistent with findings of Cushmanet al.(1977,Biochemistry16, 5484) that -CH3group substitution improves binding if the configuration isdbut diminishes binding if the configuration isl. Zinc and calcium ions released inhibition by some of the noncompetitive, but only one, of the competitive inhibitors. The noncompetitive inhibitor,l-cysteinyl(benzyl)-l-proline, and the competitive inhibitor,l-cysteinyl-l-proline, were used as affinity ligands to obtain near homogenous (25 units/mg) enzyme from human plasma. The observation that compounds with a free sulfhydryl group are competitive inhibitors and those in which the sulfhydryl groups are blocked are noncompetitive inhibitors can be rationalized if the active site of the converting enzyme is an extended linear trench.