Expression, Purification, and Characterization of Prothrombin Kringle 2

Previously, we reported that the prothrombin kringle 2 (fragment 2), induced by LPS administration into rabbit, inhibited bFGF-stimulated BCE cell growth (Lee et al., 1998). In this study, we cloned and overexpressed the kringle 2 domain of rabbit and human prothrombin as a fusion protein with the pelB leader sequence in E. coli using the T7 promoter. The fusion protein was cleaved during translocation into the periplasmic space, and cleaved recombinant protein was readily isolated from whole cell lysate by DEAE-Sepharose and Sephacryl S-200 gel filtration chromatography. Both the recombinant rabbit and human prothrombin kringle 2 showed very similar biochemical and functional characteristics to the rabbit prothrombin kringle 2 purified from rabbit serum, in terms of abnormal electrophoretic migration and endothelial cell growth inhibitory activity.