苦瓜籽蛋白的PEG/(NH_4)_2SO_4双水相分离及抑菌作用的研究  

Isolation of Momordica charantia Seed Proteins Using Polyethylene Glycol/Ammonium Sulfate Aqueoustwo-phase System and Its Antimicrobial Activity

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：《天然产物研究与开发》2011年第4期612-619,共8页Natural Product Research and Development

基　　金：青岛农大-仲恺农工学院合作研发基金(620325)

摘　　要：优化试验条件影响因素,建立PEG/(NH4)2SO4双水相系统,确定出分离苦瓜籽蛋白的最适PEG6000和(NH4)2SO4质量分数分别是22%、25%,分配系数为0.089,回收率为96%。双水相分离的苦瓜籽蛋白经SDS-PAGE凝胶电泳显示,主要蛋白质是50 KD4、3 KD和10 KD亚基结合形成的多聚体12S(327 KD)球蛋白,还原条件下出现诸多小于35 kD的蛋白组分,表明蛋白质亚基是通过二硫键结合。抑菌试验显示苦瓜籽蛋白对受试细菌菌和真菌产生明显的抑菌活性,其MIC远低于苯甲酸钠,而且在不同盐离子浓度、温度、pH及紫外线等因素处理时,均具有一定的稳定性。此外试验还表明苦瓜籽蛋白也具有较强的清除羟自由基能力和总抗氧化能力。The Momordica charantia seed proteins were extracted and separation by polyethylene glycol/ammonium sulfate aqueoustwo-phase system.The factors affecting system distribution coefficients,recycling rate,and extracting agents were investigated and the optimal conditions of M.charantia seed proteins extraction were confirmed.Under the conditions of mass fraction of PEG6000 as 22% and（NH4）2SO4 as 25%,the smallest distribution coefficient obtained as 0.089 and the recovery was 96%.The results of SDS-PAGE showed that M.charantia seed protein were polymer globulin of 12S（327 KD） with major subunits 50 KD,43 KD,and 10 KD,which were connected with disulfide bonds by low molecular weight protein subunits（35 kD）.The results of antimicrobial activities analysis showed that the proteins had strong inhibition to testing bacteria and fungi,whose MIC were far below the value of sodium benzoate,and which were very stable under the environment of low temperature,acid,ultraviolet,and inorganic salt.In addition,the test also showed total antioxidative activity and clearance on ·OH free radical of the proteins were obvious.Therefore,the M.charantia seed proteins had the significant antioxidant capacity and broad-spectrum antimicrobial activity.

关 键 词：苦瓜籽蛋白 双水相系统 分离 抑菌活性 抗氧化作用 

分 类 号：R284.2[医药卫生—中药学]