大豆蛋白质11S和7S组分及其亚基分析方法的研究述评

对大豆蛋白质组分及其亚基的分析方法进行了评述.主要内容为:利用超速离心技术把大豆蛋白质组分分为4种,以沉降系数分别表示为2S、7S、11S和15S,其中7S和11S是主要组分;利用碱溶、酸沉(冷沉)和缓冲液中沉淀的方法分别分离提取7S和11S,经凝胶过滤或离子交换柱层析提纯;利用碱溶、酸沉和离心分离方法分离提取大豆分离蛋白;利用D isc-PAGE技术初步分析7S和11S组分的个别亚基,利用SDS-PAGE技术测定7S和11S组分及其亚基的相对分子质量和相对含量;以相对分子质量为标准,在SDS-PAGE谱带中划分7S和11S组分的亚基组并测定其相对含量,然后计算7S和11S组分的相对含量和11S/7S比值.上述方法各有其优缺点和适用情况.在讨论的基础上提出食品科学与遗传育种科学要密切结合,培育含有不同蛋白质组分、不同亚基和组分比值的专用大豆品种,既可以深入研究亚基的功能特性,又能开发出新的大豆蛋白制品.

A REVIEW ON THE ANALYTICAL METHODS OF PROTEIN COMPONENTS AND ITS SUBUNITS AND THEIR APPLICATIONS IN SOYBEAN

The analytical methods of soybean protein components and subunits reported in the literature were reviewed as the following:(1) 2S,7S,11S and 15S were four components of soybean protein separated with ultracentrifuge and among them,7S and 11S were major components.(2) 11S and 7S were extracted through basic dissolving,cooling,or acidic concentration,or tris-HCI buffer concentration,then 11S and 7S were purified with gel filtration or ion exchange chromatography,respectively.(3) Soybean protein isolate was obtained through basic dissolving,acidic precipitation and centrifugal extraction.(4) Disc-PAGE was used to analysis 7S,11S and its subunits,and the content and molecular weight of 7S,11S and its subunits determined with SDS-PAGE.(5) the subunit groups and its content of 11S and 7S were determined with molecular weight criterion in bands pattern of SDS-PAGE,and then the content of 11S and 7S and 11S/7S ratio were calculated.The merits and shortcomings of the above methods were discussed for scientists to choose an appropriate method for their research purposes.It was suggested for food scientists and soybean breeders to cooperate each other for developing soybean cultivars with different kind of protein components and subunit combination specifically fitting the requirements of food industry and to provid appropriate materials for further study on functional properties of the protein components and subunits.