Abstract：In order to investigate technology of isolation and purification, and antimicrobial activity of pulp protein, in this paper, protein Mp-21.6 was isolated and purified from the pulp (Momordica charantia L.) by ammonium sulphate fractionation chromatographies on Sephadex G -100 and DEAE-52. And the protein was analyzed via SDS-PAGE and biochemical determination. The results showed that Mp-21.6 was homogeneous single band with molecular weight of 21.6 kD and pI 9.6. Mp-21.6 protein had intrachain disulfide bond by reductive two-dimensional electrophoresis. And Mp-21.6 was similar to RNMC_MOMCH[Ribonuclease MC(RNase MC, EC=3.1.27.1)] compared with amino acids by Aacomplement software. Antimicrobial activities of the protein were detected by antimicrobial testing. The results showed that Mp-21.6 protein from M. charantia had strong inhibition to testing Escherichia coli, Staphylococcus aureus, Salmonellab sp, Bacillus sabtilis,Saccharomyces cerevisiae and Aspergillus flavus respectively, whose minimal inhibitory concentration(MIC) was far below sodium benzoate value. In addition, the testing also showed that with grading separation and purification of Mp-21.6 protein from M. charantia, its total antioxidantive activity and clearance on ·OH free radical were rising. Therefore, protein Mp-21.6 has the significant antioxidant capacity and broad-spectrum antimicrobial activity. Biological active protein from M. charantia can exploit new type antimicrobial agents with development potential through grading purification by molecular weight interval fractionation way.
