Biocatalytic Properties of a Recombinant Fusarium proliferatum Lactonase with Significantly Enhanced Production by Optimal Expression in Escherichia coli.

Bing Chen; Li-Qiang Fan; Jian-He Xu; Jian Zhao; Xian Zhang; Li-Ming Ouyang

The levo-lactonase gene of Fusarium proliferatum ECU2002 (EC3.1.1.25) was cloned and expressed in Escherichia coli JM109 (DE3) for biocatalytic resolution of industrially important chiral lactones, including DL-pantoyl lactone which was a key precursor to calcium d-pantothenate. By increasing the biomass concentration and lowering the inducer (isopropyl-β- d-thiogalactoside) concentration and induction temperature, the lactonase production was significantly enhanced up to 20 kU/L, which was 20 times higher than that of wild-type strain F. proliferatum ECU2002. The recombinant Fusarium lactonase was purified using immobilized metal affinity chromatography, and its SDS-PAGE revealed a molecular mass of 50 kDa for the recombinant protein, suggesting that the enzyme was a simplex protein. Furthermore, biocatalytic properties of the recombinant lactonase were investigated, including kinetic parameters, additive’s effect, and substrate specificity. The results reported in this paper provide a feasible method to make the whole cells of E. coli JM109 (DE3) expressing lactonase gene to be a highly efficient and easy-to-make biocatalyst for asymmetric synthesis of chiral compounds.

FUSARIUM; LACTONES; RECOMBINANT proteins; ESCHERICHIA coli; GENE expression

Applied Biochemistry & Biotechnology, 2010, Vol 162, Issue 3, p744

0273-2289

Academic Journal

10.1007/s12010-009-8819-1