Molecular cloning and isolation of a recombinant alpha-Momorcharin in E. coli against Pyricularia oryzae

Introduction : Alpha-Momorcharin ( a -MMC) is a member of the ribosome-inactivating protein (RIP) family that has been widely used as an antitumor, antiviral and antifungal agent. Methods : In this study, the codons of DNA encoding a -MMC were optimized for expression in E. coli and cloned into the pET-28a(+) vector . The protein was then expressed in E. coli strain BL21 (DE3) and purified by nickel affinity chromatography. Results : Under IPTG induction, a -MMC was expressed at approximately 50% of the total protein, showing high-level recombinant protein expression in E. coli . A high amount of purified a -MMC (70 mg) was isolated from 1 L LB culture medium of E. coli BL21 (DE3) with approximately 95% purity. Interestingly, a -MMC inhibited the mycelial growth of Pyriculariaoryzae in a concentration-dependent manner. Conclusion: Using a microbial system for a -MMC expression provides a promising method for the design of a new agent against pathogens.