THE DISCOVERY AND CHARACTERIZATION OF A NOVEL NUCLEOTIDE-BASED THROMBIN INHIBITOR

Thrombin is a serine protease that plays a pivotal role in thrombosis and hemostasis, and is a major target for anticoagulation and cardiova scular disease therapy. Using a novel in vitro selection/amplification technique, we have identified a new class of thrombin inhibitors base d on single-stranded DNA (ssDNA) oligodeoxyribonucleotides (oligos). T hese thrombin inhibitors are the first example of the use of this tech nique to obtain ssDNA oligos that bind a target protein that does not interact physiologically with nucleic acid. Here, we review how iterat ive selection and amplification were used to identifiy short ssDNA seq uences that bind and inhibit thrombin (Beck et al., Nature 355 (1992) 564-566), and the tertiary structure of one aptamer sequence (Wang et al., Biochemistry 32 (1993) 1899-1904). Results from in vitro and in v ivo studies are also summarized (Griffin et al., Blood 81 (1993) 3271- 3276). The discovery of a new class of thrombin inhibitors using this technology demonstrates the power of this new approach for rapid drug discovery and development.