CONSTRUCTION，EXPRESSION AND BIOLOGICAL ASSESSMENT OF BPI23—Fcγ1 RECOMBINANT PROTEIN PROKARYOTIC EXPRESSION VECTOR

Objective. To construct pBV-BPI600-Fcγ 1700 recombinant expression vector, to transform it into Escherichia coli DH5α , and to induce the expression of BPI23-Fcγ 1 anti-bacterial recombinant protein. Methods. Genes coding for BPI23 and Fcγ 1 were amplified by RT-PCR from mRNA extracted from HL-60 cell and normal human leukocytes; recombinant cloning vector and recombinant expression vector were then constructed. pBV-BPI600-Fcγ 1700 recombinant expression vector was transformed into the competent Escherichia coli DH5α and BPI23-Fcγ 1 recombinant protein was expressed by a temperature-induced method. Results. (1) Expected amplified products BPI600bp and Fcγ 1700bp were obtained by RT-PCR method. (2) pUC18-BPI180, pUC18-BPI420 and pUC18-Fcγ 1700 recombinant cloning vectors were successfully constructed, and sequences were identical with the reported ones. (3) pBV-BPI600-Fcγ 1700 recombinant expression vector was successfully constructed, and the enzyme digestion analysis showed an expected result. (4) The expression level of BPI23-Fcγ 1 recombinant protein accounted for 20% of total bacterial proteins. (5) The renatured BPI23-Fcγ 1 recombinant protein showed bacteriocidal activity and biological function of complement fixation, and opsonization. Conclusion. pBV-BPI600-Fcγ 1700 recombinant expression vector was successfully constructed, and BPI23-Fcγ 1 recombinant protein with double biological activity of BPI and IgGFc was expressed in Escherichia coli.