Bock L C, Griffin L C, Latham J A, Vermaas E H, Toole J J
Gilead Sciences Inc., Foster City, California 94404.
Nature. 1992 Feb 6;355(6360):564-6. doi: 10.1038/355564a0.
Aptamers are double-stranded DNA or single-stranded RNA molecules that bind specific molecular targets. Large randomly generated populations can be enriched in aptamers by in vitro selection and polymerase chain reaction. But so far single-stranded DNA has not been investigated for aptamer properties, nor has a target protein been considered that does not interact physiologically with nucleic acid. Here we describe the isolation of single-stranded DNA aptamers to the protease thrombin of the blood coagulation cascade and report binding affinities in the range 25-200 nM. Sequence data from 32 thrombin aptamers, selected from a pool of DNA containing 60 nucleotides of random sequence, displayed a highly conserved 14-17-base region. Several of these aptamers at nanomolar concentrations inhibited thrombin-catalysed fibrin-clot formation in vitro using either purified fibrinogen or human plasma.
适体是能结合特定分子靶标的双链DNA或单链RNA分子。通过体外筛选和聚合酶链反应，可以从大量随机生成的群体中富集适体。但迄今为止，尚未对单链DNA的适体特性进行研究，也未考虑过与核酸无生理相互作用的靶蛋白。在此，我们描述了针对凝血级联中的蛋白酶凝血酶的单链DNA适体的分离，并报告了其结合亲和力在25 - 200 nM范围内。从含有60个随机序列核苷酸的DNA库中筛选出的32种凝血酶适体的序列数据显示，有一个高度保守的14 - 17个碱基的区域。其中几种适体在纳摩尔浓度下，使用纯化的纤维蛋白原或人血浆，在体外抑制了凝血酶催化的纤维蛋白凝块形成。
