누에체액을 이용한 E.coli 재조합 단백질(β-galactosidase) 생산성 증대

Abstract

Silkworm hemolymph increased recombinant β-galactosidase in BmN- 4/Bombyx mori nuclearpolyhedrosis virus (BmNPV) system and Spodoptera frugiperda /Autographa califomica nuclear polyhedrosis virus (AcNPV) system. E. coli is a popular host for the high-level production of recombinant proteins. So, the effect of silkworm hemolymph on recombinant protein expression in E. coli was investigated. For the reason that β-galactosidase is easy to assay, lacZ gene was inserted in expression vector, pET22b(+) and then transformed to the host cell, BL21(DE3). E. coli BL32(DE3)pET22b(+)/lacZ was cultured at various concentrations of silkworm hemolymph (0%, 1%, 3%, 5%). The expression efficiency of lacZ was determined by extracellular and intracellular β- galactosidase activity. Addition of 5% silkworm hemolymph to the culture medium increased the production of recombinant β-galactosidase by eight-fold. To identify the effective component, the silkworm hemolymph was fractionated by gel-filtration chromatography, five fractions were obtained. Among these fraction, FI and FII which are the major fraction of silkworm hemolymph were used, and the fraction FII showed a similar effect to the whole hemolymph.