酪蛋白溶解与酶解行为的动态光散射

采用动态光散射技术，以磷酸盐为缓冲液，研究了温度、离子强度和酶解行为对酪蛋白胶束平均流体力学半径(Rh)的影响规律. 结果表明，Rh值在升温过程中发生不可逆减小；随着离子强度增大，Rh值先减小再增大；酪蛋白在胰蛋白酶作用下，溶液光散射强度对应于分子量大小先急剧下降，再逐渐趋于平缓，而Rh值的变化规律与之相反；并推测了酪蛋白胶束酶解过程的结构变化模型，即由原始致密的球状体逐渐舒展为松散而规则的毛束状蛋白肽链.

The Dissolution and Enzymatic Hydrolysis of Casein by Dynamic Light Scattering

The effects of temperature,ionic strength and enzymatic hydrolysis on the average hydrodynamic radius(Rh)of casein micelles in phosphate buffer were studied by using dynamic light scattering.The results showed that the average Rh value of casein micelles was reduced irreversibly by heating.It was decreased with the increase of ionic strength in low ionic strength solution(<0.05 mol/L),but on the contrary in high ionic strength solution(>0.1 mol/L).The Rh value of casein increased rapidly during the process of enzymatic hydrolysis,and the structural model of casein in enzymatic hydrolysis was also proposed,i.e.,the casein micelle stretched into incompactly and regularly flocky peptides from compact sphere.