Expression and Characterization of Kringle 1-4.5 Domains of Human Plasminogen

ZHOU Qing-Wei, XIE Jing-Li¹, XIN Li, XU Ren, YE Qing¹, LI Zai-Ping, GAN Ren-Bao^*

( Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, the Chinese Academy of Sciences, Shanghai 200031, China;
¹State Key Lab of Bioreactor of East China University of Science and Te chnology, Shanghai 200237, China )

Abstract The cDNA encoding Kringle 1-4 and part of Kringle 5 domains of human plasminogen (K1-4.5), obtained from HepG2 by RT-PCR, was cloned into expression vector pHIL-S1. The recombinant plasmid pHIL-K1-4.5 was transformed into Pichi pastoris GS115 and the recombinant yeast was induced to express the recombinant proteins by methanol. The expressed proteins were purified by lysine affinity chromatography to a purity of 95%. The recombinant K1-4.5 inhibited the growth of bovine capillary endothelial cells (BAEC) stimulated by the basic fibroblast growth factor (bFGF), in a dosage-dependent manner with a half maximal concentration of 2 mg/L. rhK1-4.5 also inhibited 40% of the BAEC migration stimulated by bFGF in the concentration of 1 mg/L.

Key words K1-4.5; Pichia pastoris; expression; purification; bioactivity

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