Expression of the second epidermal growth factor-like domain of human factor VII in Escherichia coli

The second epidermal growth factor (EGF)-like domain of human coagulation f actor VII is a potent inhibitor of the FVIIa/tissue factor complex, the pre dominant initiator of coagulation in vivo. This domain has now for the firs t time been cloned and expressed in Escherichia coli as an affinity fusion protein. The fusion protein was secreted into the periplasm of E. coli and purified by affinity chromatography. The purified protein consisted of a fu sion protein with the expected molecular weight, and in addition, a signifi cant fraction of oligomers cross-linked by intermolecular disulfide bonds. Despite the presence of oligomers, the purified protein was a potent inhibi tor of the extrinsic blood coagulation pathway with an IC50 value of about 20 mu M. The biological activity was retained after liberation of the EGF d omain by proteolytic cleavage. (C) 1998 Elsevier Science B.V. All rights re served.