凝血酶的RNA适配体与阴离子结合外位点2结合，并改变肝素结合丝氨酸蛋白酶抑制剂对蛋白酶的抑制作用。

RNA aptamer to thrombin binds anion-binding exosite-2 and alters protease inhibition by heparin-binding serpins.

作者信息

Jeter Martha L, Ly Linda V, Fortenberry Yolanda M, Whinna Herbert C, White Rebekah R, Rusconi Christopher P, Sullenger Bruce A, Church Frank C

机构信息

Department of Pathology and Laboratory Medicine, Carolina Cardiovascular Biology Center, The University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, NC 27599-7035, USA.

出版信息

FEBS Lett. 2004 Jun 18;568(1-3):10-4. doi: 10.1016/j.febslet.2004.04.087.

DOI:10.1016/j.febslet.2004.04.087

PMID:15196911

Abstract

We studied the RNA aptamer Toggle-25/thrombin interaction during inhibition by antithrombin (AT), heparin cofactor II (HCII) and protein C inhibitor (PCI). Thrombin inhibition was reduced 3-fold by Toggle-25 for AT and HCII, but it was slightly enhanced for PCI. In the presence of glycosaminoglycans, AT and PCI had significantly reduced thrombin inhibition with Toggle-25, but it was only reduced 3-fold for HCII. This suggested that the primary effect of aptamer binding was through the heparin-binding site of thrombin, anion-binding exosite-2 (exosite-2). We localized the Toggle-25 binding site to Arg 98, Glu 169, Lys 174, Asp 175, Arg 245, and Lys 248 of exosite-2. We conclude that a RNA aptamer to thrombin exosite-2 might provide an effective clinical reagent to control heparin's anticoagulant action.

摘要

我们研究了抗凝血酶（AT）、肝素辅因子II（HCII）和蛋白C抑制剂（PCI）抑制过程中RNA适体Toggle-25与凝血酶的相互作用。Toggle-25使AT和HCII对凝血酶的抑制作用降低了3倍，但对PCI则略有增强。在存在糖胺聚糖的情况下，AT和PCI与Toggle-25一起时对凝血酶的抑制作用显著降低，但HCII仅降低了3倍。这表明适体结合的主要作用是通过凝血酶的肝素结合位点，即阴离子结合外位点-2（外位点-2）。我们将Toggle-25的结合位点定位到外位点-2的精氨酸98、谷氨酸169、赖氨酸174、天冬氨酸175、精氨酸245和赖氨酸248。我们得出结论，针对凝血酶外位点-2的RNA适体可能提供一种有效的临床试剂来控制肝素的抗凝作用。