REACTION OF SERINE PROTEASES WITH SUBSTITUTED ISOCOUMARINS - DISCOVERY OF 3,4-DICHLOROISOCOUMARIN, A NEW GENERAL MECHANISM BASED SERINE PROTEASE INHIBITOR
REACTION OF SERINE PROTEASES WITH SUBSTITUTED ISOCOUMARINS - DISCOVERY OF 3,4-DICHLOROISOCOUMARIN, A NEW GENERAL MECHANISM BASED SERINE PROTEASE INHIBITOR
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DOI：
10.1021/bi00329a005
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发表时间：
1985-01-01
期刊：
影响因子：
2.9
通讯作者：
POWERS, JC
中科院分区：
文献类型：
--
作者：
HARPER, JW;HEMMI, K;POWERS, JC
报道了含有掩蔽酰氯或酸酐部分的取代异香豆素和苯酞对许多丝氨酸蛋白酶，包括人白细胞（HL）弹性蛋白酶、组织蛋白酶G、大鼠肥大细胞蛋白酶I和II、几种人和牛凝血蛋白酶和人因子D的基于机理的失活。3，4-二氯异香豆素是这里研究的最有效的抑制剂，它使所有测试的丝氨酸蛋白酶失活，但不抑制木瓜蛋白酶、亮氨酸氨肽酶或β-氨基肽酶。内酰胺酶3，4-二氯异香豆素对HL弹性蛋白酶有相当的选择性（kobsd/[I] = 8920 M-1 s-1）;被抑制的酶对再活化相当稳定（kdeacyl = 2 × 104）。10-5 s-1），而3-acetoxyisocoumarin和3，3-dichlorophthalide抑制的酶在静置后恢复完全活性。失活的速率显着下降，在可逆的抑制剂或底物的存在下，和紫外光谱测量表明，失活后的异香豆素环结构丢失。胰凝乳蛋白酶A γ被1.2当量的3-氯异香豆素或3，4-二氯异香豆素完全灭活，灭活后释放1当量质子。显然，这些化合物与丝氨酸蛋白酶反应以释放可使另一活性位点残基酰化的反应性酰氯部分。这些是第一个机制为基础的抑制剂报告的许多酶的测试，和3，4-二氯异香豆素应该找到广泛的适用性作为一个一般的丝氨酸蛋白酶抑制剂。
The mechanism-based inactivations of a number of serine proteases, including human leukocyte (HL) elastase, cathepsin G, rat mast cell proteases I and II, several human and bovine blood coagulation proteases, and human factor D by substituted isocoumarins and phthalides which contain masked acyl chloride or anhydride moieties, are reported. 3,4-Dichloroisocoumarin, the most potent inhibitor investigated here, inactivated all the serine proteases tested but did not inhibit papain, leucine aminopeptidase or .beta.-lactamase. 3,4-Dichloroisocoumarin was fairly selective toward HL elastase (kobsd/[I] = 8920 M-1 s-1); the inhibited enzyme was quite stable to reactivation (kdeacyl = 2 .times. 10-5 s-1), while enzymes inhibited by 3-acetoxyisocoumarin and 3,3-dichlorophthalide regained full activity upon standing. The rate of inactivation was decreased dramatically in the presence of reversible inhibitors or substrates, and ultraviolet spectral measurements indicate that the isocoumarin ring structure is lost upon inactivation. Chymotrypsin A.gamma. is totally inactivated by 1.2 equiv of 3-chloroisocoumarin or 3,4-dichloroisocoumarin, and .apprx. 1 equiv of protons is released upon inactivation. Apparently, these compounds react with serine proteases to release a reactive acyl chloride moiety which can acylate another active site residue. These are the first mechanism-based inhibitors reported for many of the enzymes tested, and 3,4-dichloroisocoumarin should find wide applicability as a general serine protease inhibitor.