牦牛乳中主要过敏原的分离纯化

为研究牦牛乳蛋白质的过敏性,用化学方法分离牦牛乳中主要的过敏原蛋白质,采用快速蛋白纯化系统(FPLC)结合凝胶层析技术对分离出的蛋白质进行纯化．在牦牛脱脂乳中添加10％醋酸至酪蛋白的等电点pH46,使酪蛋白和乳清蛋白分离．根据酪蛋白在尿素溶液中的溶解度和对钙的敏感性不同,对酪蛋白进行粗分级,得到αs酪蛋白和β酪蛋白．应用离子交换色谱和葡聚凝胶sephadex G100进一步纯化粗分级得到的酪蛋白,得到αscasein和β酪蛋白．以柠檬酸钠为螯合剂、在低pH并有盐存在的条件下从酸乳清中分离出β乳球蛋白,FPLC纯化后用RPHPLC检测其纯度,得到αscasein和β酪蛋白纯度分别为8713％和8858％,β乳球蛋白的纯度为8000％．

Separation and purification of major allergens in yak milk

The major allergens in yak milk were obtained by chemical methods,and purified by a fast protein liquid chromatography(FPLC) combined gel chromatography in order to analyze allergenicity of protein in yak milk.Casein and whey were isolated after adjusting isoelectric precipitating of skimmed milk to 4.6 by adding 10% acetic acid.Based on differential solubility in urea solutions and differential sensitivity of calcium,αs-casein and β-casein were separated from whole casein.And then,the crude fractions of αs-casein,β-casein were further separated using anion-exchange FPLC and Sephadex G100 column.β-lactoglobulin was separated from acid whey using chelating of citrate sodium at low pH in the presence of salt and purified by FPLC.The results of RP-HPLC showed that the purities of αs-,β-casein,and β-lactoglobulin were 87.13%,88.58%,and 80.00%,respectively.