title: Application of combinatorial libraries and protein engineering to the discovery of novel anti-thrombotic drugs.
abstract: Combinatorial libraries and protein engineering represent two new powerful tools in drug discovery and development. The application of a combinatorial ssDNA library to thrombin led to the discovery of a sequence-specific nucleotide-based thrombin inhibitor (thrombin aptamer). The thrombin aptamer has a novel tertiary structure revealed by NMR and shows potent rapid anticoagulation with a short half-life in vivo. It has been used successfully to replace heparin in a canine cardiopulmonary bypass model. Functional mapping of the surface residues of thrombin led to the generation of a modified thrombin with markedly diminished procoagulant properties while retaining its ability to activate protein C. This engineered thrombin functions as a protein C activator and demonstrates potent anticoagulation in vivo without prolongation of the bleeding time.
authors.affiliation: Department of Medicine, Stanford University Medical School, CA, USA.
authors.forename: L L
authors.initials: LL
authors.lastname: Leung
mesh_terms: D000800:Angioplasty, Balloon / Q000009:adverse effects; D000818:Animals; D052157:Aptamers, Nucleotide; D001483:Base Sequence; D001665:Binding Sites; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D016384:Consensus Sequence; D004277:DNA, Single-Stranded / Q000235:genetics / Q000378:metabolism; D004285:Dogs; D015195:Drug Design; D005343:Fibrinolytic Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D008252:Macaca fascicularis; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides; D016133:Polymerase Chain Reaction; D011119:Polynucleotides / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D011485:Protein Binding; D015202:Protein Engineering; D011817:Rabbits; D013329:Structure-Activity Relationship; D013917:Thrombin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013927:Thrombosis / Q000517:prevention & control
chemical_list: D052157:Aptamers, Nucleotide; D004277:DNA, Single-Stranded; D005343:Fibrinolytic Agents; D009841:Oligonucleotides; D011119:Polynucleotides; C081676:thrombin aptamer; D013917:Thrombin