大豆原料及其分离蛋白的SDS-PAGE图谱研究

SDS-PAGE Patterns of Soybean, Defatted Soy bean And Soybean Prorein Isolates

将大豆原料制备成脱脂豆粕、“碱提酸沉”分离蛋白和超滤法分高蛋白，采用SDS－PAGE技术研究其中的电泳图谱变化。在所有样品的SDS－PAGE图谱中共分离出17种蛋白组分。其分子量（Mr）分别是：1号带，22840：(2，3)号带，26020：4号带，30080：5号带，32820：（6、7）号带，36850；8号带，46500：9号带，5143010号带，5692011号带，65790：12号带，70740；13号带，76060：（14、15、16）号带，9050017号带，104620。大豆原料中有16个蛋白质组分，制备成脱脂豆粕和分高蛋白后出现17号新带，同时消失11、12、13号带。用热处理和β-巯基乙醇处理样品证明了17号新带是由对热切感的蛋白质以二硫键的形式聚合而成。11、12、13号带是对热最敏感的蛋白质，一经加热都会消失，（14、15、16）这一组蛋白组分以及5号带、7号带，对热的敏感性不如11、12、13号带，但随着加热时间的延长，在SDS－PAGE图谱上也会逐渐消失。脱脂豆粕中，还消失了1号带，“碱提酸沉”大豆分离蛋白中消失了4、7号带，超滤法的大豆分离蛋白消失了1、2号带。这些SDS－PAGE图谱的变化，与三种制品各自的工艺特点有关。

Soy protein isolates were prepared from soybean by methods of ultrafiltration and sediment at isoelectric pH. The SDS-PAGE patterns of sognilk, defatted soybean and soy protein isolates smples were analyzed. 17 bands of soy proteins were fed in all of the SDS-PAGE patterns.In all of the propared smples, band l7 with ar 104620 was formed as the only new one and some thermal sensitive bands such as band 13 with Mr 76060, band 12 with ar 70740 and band 5 with Mr 32820 disappeared. It was found ty heating and β -mercaptoethanol treatment that the change of sulfhydryl bond was attributed to this coanon SDS-PAGE pattern change. The SDS-PAGE patterns of soy protein also exited some changes when soybean was prepared as defatted soybean and protein isolates- sand 1 in defatted soybean, band 4, 7 in the protein isolates produced by sediment at isoelectric pH and band 1, 2 in the protein isolates produced by ultrafiltration were found disrmeared. The various characteristics chanqes were related to these changes processing.