脂肪氧合酶催化亚油酸氧化对酸沉大豆蛋白理化性质的影响(Ⅱ)--聚集体的相对分子质量分布  

Effects of Linoleic Acid Oxidation Catalyzed by Lipoxidase on Physical/Chemical Properties of Soybean Proteins(Ⅱ):Molecular Weight Distribution of Aggregates

作　　者：黄友如[1] 华欲飞[2] 韩曜平[1] 顾建华[1] 陈义勇[1] 

机构地区：[1]常熟理工学院生物与食品工程系,常熟215500 [2]江南大学食品学院,无锡214036

出　　处：《中国粮油学报》2008年第5期38-41,共4页Journal of the Chinese Cereals and Oils Association

基　　金：国家自然科学资金项目(20476040)

摘　　要：模拟大豆蛋白质制备过程,应用毛细管电泳和凝胶体积排阻色谱探讨了脂肪氧合酶催化亚油酸氧化诱导的大豆蛋白质聚集体的相对分子质量分布。毛细管电泳分析表明,随着反应的进行,酸沉大豆蛋白各亚基的迁移时间延长、峰形展宽,说明反应后大豆蛋白各亚基的构象发生了改变,且随着模拟体系反应时间的延长,形成C-C或C-N共价交联形式聚集体的相对分子质量增大、数量增加。凝胶体积排阻色谱分析表明,酸沉大豆蛋白的相对分子质量随反应时间延长而增加,且分布具有多态性。这些数据说明模拟反应体系中的蛋白质聚集行为和聚集程度随反应时间的不同而不同。Soybean proteins were prepared by means of isoelectric precipitation using hydrochloric acid as precipitant in a model system. And the effect of linoleic acid oxidation catalyzed by lipoxidase on the physical/chemical properties of the proteins was investigated by capillary electrophoresis （SDS- CE） and high performance size exclusion chromatography （SEC - HPLC）. Results： SDS - CE reveals that the migration time of protein subtmits become prolonged and peak shape broadened while the reaction proceeds. It is indicated that the conformation of soybean protein subunits is changed after the reaction, C - C or C - N linkages are formed between protein molecules and polymerization is promoted in the reacted samples. SEC - HPLC analysis shows that the molecular weight becomes larger after the reaction and the molecular weight distribution presents the same poly- dispersed distribution as it is found in laser light scattering （previous paper）. This implies that the aggregating behavior and degree of the soybean protein change with the reaction time.

关 键 词：大豆蛋白 脂肪氧合酶 亚油酸 聚集体 理化性质 分子质量分布 

分 类 号：O643.32[理学—物理化学] TQ333.1[理学—化学]