苦瓜Mp-21.6蛋白的分离及生化特性  

Separation and Biochemical Properties of Protein Mp-21.6 from Momordica charantia

作　　者：蔡马[1] 于群[2] 朱新产[2] 

机构地区：[1]仲恺农业工程学院生命科学学院,广州510225 [2]青岛农业大学生命科学学院,青岛266109

出　　处：《农业生物技术学报》2011年第5期823-831,共9页Journal of Agricultural Biotechnology

基　　金：青岛农大-仲恺农工学院合作研发基金(No.620325)资助

摘　　要：为研究苦瓜蛋白的有效分离技术与抑菌活性,本实验采用(NH4)2SO4分级分离油苦瓜(Momordic a charantiaL.)蛋白质,将SephadexG-100凝胶柱在DEAE-52阴离子交换柱色谱工作站上串联,分步聚集纯化出苦瓜蛋白Mp-21.6。SDS-PAGE凝胶电泳显示单一蛋白条带;经生化分析鉴定,Mp-21.6(Momordica protein of 21.6kD)蛋白的分子量为21.6kD,等电点pI=9.6;双向还原SDS-PAGE确定苦瓜蛋白Mp-21.6仅存在链内二硫健;Aacomplement软件的基于氨基酸组成比较发现,Mp-21.6类似于RNMC_MOMCH[Ribonuclease MC (RNase MC,EC=3.1.27.1)]。抑菌试验显示Mp-21.6对大肠杆菌(Escherichia coli)、金黄色葡萄球菌(Staphylococcus aureus)、沙门氏菌(Salmonellab sp)、枯草芽胞杆菌(Bacillus sabtilis)、啤酒酵母(Saccharomyces cerevisiae)和黄曲霉(Aspergillus flavus)产生明显的抑菌活性,其最小抑菌浓度(MIC)远低于苯甲酸钠。随着苦瓜蛋白的逐级分离纯化,其清除羟自由基和总抗氧化能力均有上升的趋势。研究结果提示,苦瓜Mp-21.6蛋白具有广谱抗菌活性及显著的抗氧化能力,利用区隔性分离方式,分级提纯苦瓜的生物活性蛋白,将能开发出有发展潜力的新型抗菌药物。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 wererising. 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.

关 键 词：苦瓜 Mp-21.6蛋白 分离纯化 抑菌活性 抗氧化作用 

分 类 号：S511[农业科学—作物学]