earticle

영어

A recombinant Escherichia coli harboring heterologous styrene monooxygenase (SMO) genes under the control of T7 promoter produced protein inclusion bodies extensively and exhibited a low SMO activity. To express SMO in soluble form and increase the whole-cell SMO activity, various chaperones including DnaK-DnaJ-GrpE, GroES-GroEL and trigger factor were co-expressed in the recombinant E. coli individually or in combinations. Co-expression of chaperones improved the SMO activity greatly, especially with combined expression of DnaK-DnaJ-GrpE and GroESGroEL as 180 U/g cell, which was almost 2-fold higher than the one without chaperons overexpression. According to SDS-PAGE analysis, the production of SMO proteins in the soluble fraction of cell lysate increased by chaperones co-expression. The high SMO activity was maintained during water-organic two-phase experiment for 12 h, which
yielded 170 mM enantiopure (S)-styrene oxide in organic phase. This study illustrates that chaperones co-expression can be an efficient strategy for the development of an active whole-cell biocatalyst.