牦牛与奶牛酪蛋白制备的CPPs分子量分布及其生物功能研究

牦牛或奶牛酪蛋白CPPs粗制品，经阴离子交换精制后获得的高磷组分具有相似的高效分子排阻层析（HPSEC）谱图，均分离出3个峰，分子量依次在15000-16500u之间、4000-5000u之间及2500u左右。采用体外消化模拟实验研究了CPPs样品的促钙吸收能力，证实牦牛与奶牛酪蛋白CPPs在促钙吸收能力方面无明显差异。探讨了CPPs制品的促钙吸收能力与r（N／P）、分子量大小分布之间的关系，结果表明：牦牛与奶牛酪蛋白CPPs的r（N／P）值越小其促钙吸收能力越强，而且分子量小于5000u组分在CPPs制品中所占百分率增加，则其r（N／P）呈下降趋势。

Research on molecule weight distribution and biological function of the CPPs from yak and milch cow casein

Two similar chromatograms could be given for the ion-exchange purified yak and milch cow casein phosphopeptides(CPPs) by High Performing Size Exclusion Chromatograghy,for each sample,three components were separated and the molecule weight distribution were found to be 15 000~16 500 u,4 000~5 000 u and about 2 500 u respectively;By gastrointestinal simulating experiments in vitro,no difference of the Ca2+-promoted absorbency existed in evidence between CPPs of yak and milch cow caseins.In addition,the relations between the the molecular weight distribution,the Ca2+-promoted absorbency ability and the r(N/P) of CPPs were investigated,it indicated that the r(N/P) of each CPPs was less,the better was its Ca2+-promoted absorbency ability and also the r(N/P) of CPPs trend to reduce while the percentage of the components with a molecular weight less than 5 000 u increased.