Rational design of a potent anticoagulant thrombin.
Thrombin acts as a procoagulant when it cleaves fibrinogen and promotes the formation of a fibrin clot and functions as an anticoagulant when it activates protein C with the assistance of the cofactor thrombomodulin. The dual function of thrombin in the blood poses the challenge to turn the enzyme into a potent anticoagulant by selectively abrogating fibrinogen cleavage. Using functional and structural data, we have rationally designed a thrombin mutant, W215A/E217A, that cleaves fibrinogen with a value of k(cat)/K(m) about 20,000-fold slower than wild-type but activates protein C in the presence of thrombomodulin with a specificity comparable with wild-type. This mutant demonstrates for the first time that the relative specificity of thrombin toward fibrinogen and protein C can be completely reversed.
Cantwell
A M
AM
Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Di Cera
E
E
D000925:Anticoagulants / Q000737:chemistry*; D015195:Drug Design; D006801:Humans; D016297:Mutagenesis, Site-Directed; D013917:Thrombin / Q000737:chemistry* / Q000235:genetics
D000925:Anticoagulants; D013917:Thrombin