Adsorption behavior of milk proteins on polystyrene latex. A study based on sedimentation field-flow fractionation and dynamic light scattering.
Adsorption behavior of milk proteins on polystyrene latex. A study based on sedimentation field-flow fractionation and dynamic light scattering.
复制标题
牛奶蛋白在聚苯乙烯乳胶上的吸附行为。
DOI：
10.1016/0021-9673(92)85529-3
复制
发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Dalglesih,DG
中科院分区：
文献类型：
--
作者：
Caldwell,KD;Li,J;Li,JT;Dalglesih,DG
用沉降场流动分馏技术表征了蛋白质β-酪蛋白(BCN)或β-乳球蛋白(BLG)在胶体聚苯乙烯胶乳上的吸附行为，并用该系统模拟了蛋白质稳定乳状液中蛋白质与脂肪液滴表面的疏水相互作用。研究发现，SdFFF技术可以直接测定BCN和BLG不可逆吸附在胶乳表面的表面浓度，只要注意将载体的离子强度保持在抑制分离通道中颗粒壁斥力的水平。测得的两种蛋白质的表面浓度相似(约1 mg/m2)，并通过氨基酸定量分析证实了这一点。这些浓度低于消耗研究中发现的浓度(BCN和BLG分别为3 mg/m2和4 mg/m2)，其中松散结合蛋白可能已包括在测定中。动态光散射法测定了两种蛋白质的吸附层厚度，发现两种蛋白质的吸附层厚度有显著差异(BCN为15 nm，BLG为2−3 nm)。根据这两种蛋白质不同的表面排列，讨论了这些发现的含义。
Sedimentation field-flow fractionation (SdFFF) has been used to characterize the adsorption of the proteins β-casein (BCN) or β-lactoglobulin (BLG) on colloidal polystyrene latices; this system was used to model hydrophobic interactions between the proteins and the surfaces of fat droplets in protein-stabilized emulsions. It was found that the SdFFF technique could determine directly the surface concentrations of BCN and BLG irreversibly adsorbed to the latex surface, provided care was taken to maintain the ionic strength of the carrier at a level which suppressed particle-wall repulsion in the separation channel. The measured surface concentrations were similar for the two proteins (about 1 mg/m2), and this was verified by quantitative amino acid analysis. These concentrations were smaller than those found in depletion studies (3 and 4 mg/m2respectively for BCN and BLG), in which loosely associated protein may have been included in the determinations. The thickness of the adsorbed layers was determinedin situby dynamic light scattering and was found to differ significantly for the two proteins (up to 15 nm for BCN vs. 2−3 nm for BLG). The implication of these findings in terms of different surface arrangements of the two proteins is discussed.