Optimization of expression conditions and activity verification of Musca domestica antifungal peptide-1 in prokaryotic cells

Objective To optimize expression conditions of Musca domestica antifungal peptide-1(MAF-1)in prokaryotic cells and to verify the activity of the recombinant fusion protein.Methods Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)and Quantity One image analysis system were used to study the effect of different temperature,concentration and time of isopropyl-β-D-galactosidase(IPTG)induction on the expression of fusion protein of MAF-1.The purification of the fusion protein was performed with nickel chelating affinity chromatography and the activity of purified fusion protein was verified after the excision the histidine(His)-tagged protein.Results The expression of the fusion protein reached the highest level of 0.706 mg/mL and a minimum inhibitory concentration of 70μg/mL for Candida albicans under the IPTG concentration of 25μmol/L and an induction time of 18 hours at the temperature of 34℃.Conclusion The optimistic conditions for MAF-1 prokaryotic expression were successfully ascertained and the purified protein exhibited antifungal activity after His-tagged protein excision.