Woodruff R S, Ivanov I, Verhamme I M, Sun M-F, Gailani D, Sullenger B A
Department of Surgery, Duke University Medical Center, Durham, NC, United States; University Program in Genetics and Genomics, Duke University, Durham, NC, United States.
Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States.
Thromb Res. 2017 Aug;156:134-141. doi: 10.1016/j.thromres.2017.06.015. Epub 2017 Jun 9.
The plasma protease factor XIa (FXIa) has become a target of interest for therapeutics designed to prevent or treat thrombotic disorders.
We used a solution-based, directed evolution approach called systematic evolution of ligands by exponential enrichment (SELEX) to isolate RNA aptamers that target the FXIa catalytic domain.
Two aptamers, designated 11.16 and 12.7, were identified that bound to previously identified anion binding and serpin bindings sites on the FXIa catalytic domain. The aptamers were non-competitive inhibitors of FXIa cleavage of a tripeptide chromogenic substrate and of FXIa activation of factor IX. In normal human plasma, aptamer 12.7 significantly prolonged the aPTT clotting time.
The results show that novel inhibitors of FXIa can be prepared using SELEX techniques. RNA aptamers can bind to distinct sites on the FXIa catalytic domain and noncompetitively inhibit FXIa activity toward its primary macromolecular substrate factor IX with different levels of potency. Such compounds can be developed for use as therapeutic inhibitors.
血浆蛋白酶因子XIa（FXIa）已成为旨在预防或治疗血栓性疾病的治疗药物的关注靶点。
我们采用一种基于溶液的定向进化方法，即指数富集配体系统进化技术（SELEX）来分离靶向FXIa催化结构域的RNA适配体。
鉴定出两种分别命名为11.16和12.7的适配体，它们与先前确定的FXIa催化结构域上的阴离子结合位点和丝氨酸蛋白酶抑制剂结合位点结合。这些适配体是FXIa切割三肽显色底物以及FXIa激活因子IX的非竞争性抑制剂。在正常人血浆中，适配体12.7显著延长了活化部分凝血活酶时间（aPTT）的凝血时间。
结果表明，可使用SELEX技术制备新型FXIa抑制剂。RNA适配体可结合到FXIa催化结构域上的不同位点，并以不同效力水平非竞争性抑制FXIa对其主要大分子底物因子IX的活性。此类化合物可开发用作治疗性抑制剂。
