Research on PEGylation of porcine prothrombin for improving biostability and reducing animal immunogenicity

Prothrombin is a vitamin K-dependent serine protease and plays pivotal roles in both procoagulant and anticoagulant pathway of hemostasis. In this study, prothrombin purified from porcine plasma was modified through PEGylation at N-terminal residue using 40 kDa PEG-phenyl-isothiocyanate (PIT-PEG40K). The monoPEGylated prothrombin enhanced biostability and remarkably prolonged circulating half-life in mice as compared with that of the nonmodified prothrombin. Moreover, the immunogenicity of PEGylated prothrombin in mice is significantly decreased compared to nonmodified prothrombin. These studies demonstrated the feasibility of PEGylating prothrombin as a promising way for the development of new prothrombin drugs.

Biological activity assay of prothrombin. The capabilities of fibrinogen-lowering after subcutaneous administration of prothrombin or PEG-prothrombin at a dose of 50 μg/kg. Plasma levels of the fibrinogen were measured by ELISA kit, data are means ± SD for five mice per group.Figure optionsDownload as PowerPoint slide