1. Activation of prothrombin Barcelona. Evidence for active high molecular weight intermediates
- Author
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Marie-Josèphe Rabiet, Dominique Labie, F. Josso, Jacques Elion, and Richard Benarous
- Subjects
Isoflurophate ,Stereochemistry ,Biophysics ,Hirudin ,Viper Venoms ,Cleavage (embryo) ,Biochemistry ,Models, Biological ,Thrombin ,medicine ,Molecule ,Humans ,Molecular Biology ,Binding Sites ,biology ,Chemistry ,Active site ,Genetic Variation ,Hirudins ,Enzyme Activation ,Molecular Weight ,Factor X ,biology.protein ,Prothrombin Time ,Prothrombin ,circulatory and respiratory physiology ,medicine.drug ,Prothrombin Barcelona - Abstract
Prothrombin Barcelona is a varient of human prothrombin. Its activation by factor Xa is characterized by two abnormal features. The first one is the absence of one of the two Xa-catalyzed cleavages, and the second one the generation of a thrombin-like activity responsible for the thrombin-catalyzed cleavages on the prothrombin molecule and for the activity toward small substrates but without clotting activity. The molecular species exhibiting the thrombin-like activity have been characterized Diisopropyl phosphofluoridate incorporation experiments show that upon activation, two high molecular weight intermediates bearing an active site are formed: one has the molecular weight of prothrombin, the other of prethrombin 1. In the presence of hirudin, only the first intermediate is formed due to a single cleavage by factor Xa which is therefore responsible for the unmasking of the active site.
- Published
- 1979