In this study, the interaction and binding behavior of anesthetic tetracaine (TET) with bovine β-lactoglobulin (LGB) isoform A and a mixture of isoforms A and B were investigated under varying environmental conditions (pH, ionic strength, concentration, LGB-TET complex molar ratio). A wide range of analytical techniques (dynamic light scattering (DLS), electrophoretic mobility, UV–Vis spectroscopy, circular dichroism (CD), quartz crystal microbalance (QCM-D) were used to analyze the physicochemical properties of the complexes in bulk solution and on the surface of gold. The experiments revealed that TET, which is amphiphilic, could bind with LGB not only in the β-barrel but also onto the surface. The zeta potential of the LGB becomes more positively charged upon interaction with TET due to electrostatic interaction of the amino group present in the TET structure. Changes in the zeta potential values are mostly visible above pH 6 for all tested systems. CD spectra show that interaction with the ligand does not change the secondary structure of the protein. The physicochemical properties of LGB-TET complex were examined in an adsorbed state on a gold surface using the QCM-D method. Additionally, molecular docking was used to evaluate the most likely binding site for TET with LGB.

在这项研究中，研究了麻醉性丁卡因（TET）与牛β-乳球蛋白（LGB）同工型A和同工型A和B的混合物在不同环境条件（pH，离子强度，浓度，LGB-TET）下的相互作用和结合行为复数摩尔比）。广泛的分析技术（动态光散射（DLS），电泳迁移率，UV-Vis光谱，圆二色性（CD），石英晶体微量天平（QCM-D））用于分析散装溶液中配合物的理化性质和实验表明，两亲性TET不仅可以在β-桶中与LGB结合，而且可以与表面上的LGB结合。由于存在于TET结构中的氨基的静电相互作用，LGB的zeta电位在与TET相互作用时变得更带正电。在所有测试系统中，pH高于6时，zeta电位值的变化几乎都是可见的。CD谱显示与配体的相互作用不会改变蛋白质的二级结构。使用QCM-D方法在金表面上的吸附状态下检查了LGB-TET复合物的理化性质。此外，分子对接用于评估TET与LGB的最可能结合位点。使用QCM-D方法在金表面上的吸附状态下检查了LGB-TET复合物的理化性质。此外，分子对接用于评估TET与LGB的最可能结合位点。使用QCM-D方法在金表面上的吸附状态下检查了LGB-TET复合物的理化性质。此外，分子对接用于评估TET与LGB的最可能结合位点。