Max-Planck-Institut für Kolloid- und Grenzflächenforschung, 14424 Potsdam, Germany.
Institute of Colloid Chemistry and Chemistry of Water, Kiev 03680, Ukraine.
Adv Colloid Interface Sci. 2015 Aug;222:509-16. doi: 10.1016/j.cis.2015.01.004. Epub 2015 Jan 26.
The equations of state, adsorption isotherms and functions of the distribution of protein molecules in liquid interfacial layers with respect to molar area and the equations for their viscoelastic behavior are presented. This theory was used to determine the adsorption characteristics of β-casein and β-lactoglobulin at water/oil interfaces. The experimental results are shown to be describable quite adequately by the proposed theory with consistent model parameters. The data analysis demonstrated that the β-casein molecule adsorbed at equilibrium conditions is more unfolded as compared with dynamic conditions, and this fact causes the significant increase of the adsorption equilibrium constant. The theory assumes the adsorption of protein molecules from the aqueous solution and a competitive adsorption of alkane molecules from the alkane phase. The comparison of the experimental equilibrium interfacial tension isotherms for β-lactoglobulin at the solution/hexane interface with data calculated using the proposed theoretical model demonstrates that the assumption of a competitive adsorption is essential, and the influence of the hexane molecules on the shape of the adsorption isotherm does in fact exist.
本文提出了蛋白质分子在液-界面层中摩尔面积相关的状态方程、吸附等温线和分布函数，以及它们的粘弹性行为方程。该理论用于确定β-乳球蛋白和β-酪蛋白在油水界面上的吸附特性。实验结果表明，提出的理论可以很好地描述实验结果，且具有一致的模型参数。数据分析表明，与动态条件相比，β-酪蛋白分子在平衡条件下的吸附更为展开，这一事实导致吸附平衡常数显著增加。该理论假设蛋白质分子从水溶液中吸附，并与从烷烃相竞争吸附的烷烃分子。β-乳球蛋白在溶液/己烷界面上的实验平衡界面张力等温线与使用所提出的理论模型计算的数据进行比较，表明竞争吸附的假设是必要的，实际上，己烷分子会影响吸附等温线的形状。
