TẠO DÒNG VÀ BIỂU HIỆN PROTEIN KOJA DUNG HỢP VỚI SUMO TRÊN ESCHERICHIA COLI

Abstract

Background: Kojic acid is a skin-lightening agent extensively used in cosmetic products. Kojic acid is produced by fungal fermentation, which is time-consuming, thus elevating the product’s price. Recent studies in Aspergillus oryzae idicated that gene kojA encodes for a protein involved in the synthesis of kojic acid using glucose as substrate. Objectives: This study aims to express recombinant KojA fused with SUMO in Escherichia coli. Methods: Plasmid pET-SUMO-KojA was transformed into E. coli BL21(DE3) for the expression of KojA protein with SUMO tag. KojA as inclusion bodies was dissolved and purified by IMAC. Results: The transformed bacteria can express KojA with high yield, nevertheless as inclusion bodies (TB medium, 0.1 mM IPTG at 25°C). Inclusion bodies could be dissolved in buffer containing 6 M urea, pH 12 at 25°C and purified by IMAC with the final yield of 37 mg/L culture. Conclusions: In this study, we have successfully transformed E. coli BL21(DE3) with the recombinant plasmid pET-SUMO-kojA. The bacteria expressed KojA with high amount in inclusion bodies. The insoluble protein could be completely dissolved and the pure protein obtained by 1-step purification using Ni-Sepharose column.