Expression of human plasminogen kringle 5 as fusion protein with truncated hIFN gamma gene in Escherichia coli

摘要

The human interferon gamma (hIFNgamma) gene was used as a fusion partner to mediate the expression of heterologous proteins and the effect of the fusion partner length on the expression of the heterologous protein was researched. Plasminogen kringle 5 (pk5), an inhibitor of angiogenesis, was fused to hIFNgamma and its serially truncated fragments, respectively, and the expression of fusion proteins was determined by SDS-Page gel. The pk5 protein was obtained readily by the introduction of sequences recognized by protease factor Xa at the fusion site and ion-exchange chromatography was employed to purify pk5. The recovery of the biological activities of pk5 was studied using the orthogonal experimental design L-9 (3(4)) (four factors, three levels, nine experiments) and evaluated by measurement of anti-endothelial cell proliferation in vitro.