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

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

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。

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 Ca^2＋ -promoted absorbency existed in evidence between CPPs of yak and milch cow caseins. In addition, the relations between the the molecular weight distribution, the Ca^2＋ -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 Ca^2＋ -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.