环仿酰胺A对凝血酶及其他胰蛋白酶样丝氨酸蛋白酶的抑制作用

Inhibition of thrombin and other trypsin-like serine proteinases by cyclotheonamide A.

作者信息

Lewis S D, Ng A S, Baldwin J J, Fusetani N, Naylor A M, Shafer J A

机构信息

Department of Biological Chemistry, Merck Research Laboratories, West Point, Pennsylvania 19486.

出版信息

Thromb Res. 1993 Apr 15;70(2):173-90. doi: 10.1016/0049-3848(93)90158-k.

DOI:10.1016/0049-3848(93)90158-k

PMID:8322286

Abstract

Cyclotheonamide A (CA), a cyclic peptide isolated from the marine sponge of the genus Theonella was shown to be a slow-binding inhibitor of several trypsin-like serine proteinases. Values of 4.6 x 10(4), 4.8 x 10(4), 9.3 x 10(3), 2.1 x 10(3) and 2.7 x 10(2) M-1 s-1 were determined for the second-order rate constants for formation of CA complexes with thrombin, trypsin, plasmin, 2-chain t-PA and factor Xa, respectively. The equilibrium constant (Ki) was measured for dissociation of CA from the CA complex with human thrombin (Ki = 1.0 nM), bovine trypsin (Ki = 0.2 nM), human plasmin (Ki = 12 nM), human factor Xa (Ki = 50 nM) and human 2-chain tissue plasminogen activator (t-PA) (Ki = 40 nM). CA produces dose dependent increases in clotting time assays. The clotting time in the thrombin time, activated partial thromboplastin time and prothrombin time assays, were doubled by 1.5, 0.9 and 48 microM CA, respectively. A model for the binding of CA to the active site of thrombin is proposed.

摘要

环丝氨酸酰胺A（CA）是从西奥海绵属的海洋海绵中分离出的一种环肽，它被证明是几种胰蛋白酶样丝氨酸蛋白酶的慢结合抑制剂。与凝血酶、胰蛋白酶、纤溶酶、双链组织型纤溶酶原激活剂（t-PA）和因子Xa形成CA复合物的二级速率常数分别测定为4.6×10⁴、4.8×10⁴、9.3×10³、2.1×10³和2.7×10²M⁻¹ s⁻¹。测定了CA从与人凝血酶（Ki = 1.0 nM）、牛胰蛋白酶（Ki = 0.2 nM）、人纤溶酶（Ki = 12 nM）、人因子Xa（Ki = 50 nM）和人双链组织型纤溶酶原激活剂（t-PA）（Ki = 40 nM）的CA复合物中解离的平衡常数（Ki）。在凝血时间测定中，CA产生剂量依赖性的凝血时间增加。在凝血酶时间、活化部分凝血活酶时间和凝血酶原时间测定中，凝血时间分别在1.5、0.9和48 microM CA作用下加倍。提出了CA与凝血酶活性位点结合的模型。