School of Chemistry and Chemical Engineering, Guangdong Provincial Key Lab for Green Chemical Product Technology, South China University of Technology, Guangzhou 510640, P. R. China.
Langmuir. 2023 Aug 1;39(30):10701-10710. doi: 10.1021/acs.langmuir.3c01541. Epub 2023 Jul 20.
Protein adsorption at oil-water interfaces has received much attention in applications of food emulsion and biocatalysis. The protein activity is influenced by the protein orientation and conformation. The oil polarity is expected to influence the orientation and conformation of adsorbed proteins by modulating intermolecular interactions. Hence, it is possible to tune the protein emulsion stability and activity by varying the oil polarity. Martini v3.0-based coarse-grained molecular dynamics (CGMD) simulations were employed to investigate the effect of oil polarity on the orientation and conformation of hydrophobin (HFBI) and lipase B (CALB) adsorbed at triolein-water, hexadecane-water, and octanol-water interfaces for the first time. The protein adsorption orientation was predicted through the hydrophobic dipole, indicating that protein adsorption exists in preferred orientations at hydrophobic oil interfaces. The conformation of the adsorbed HFBI is well conserved, whereas relatively larger conformational changes occur during the CALB adsorption as the oil hydrophobicity increases. Comparisons on the adsorption interaction energy of proteins with oils confirm the relationship between the oil polarity and the interaction strength of proteins with oils. In addition, CGMD simulations allow longer time scale simulations of the behaviors of protein adsorption at oil-water interfaces.
蛋白质在油水界面的吸附在食品乳液和生物催化的应用中受到了广泛关注。蛋白质的活性受到蛋白质取向和构象的影响。油的极性有望通过调节分子间相互作用来影响吸附蛋白质的取向和构象。因此，可以通过改变油的极性来调节蛋白质乳液的稳定性和活性。首次使用基于 Martini v3.0 的粗粒化分子动力学（CGMD）模拟研究了油极性对三油酸甘油酯-水、十六烷-水和辛醇-水界面上吸附的亲脂蛋白（HFBI）和脂肪酶 B（CALB）的取向和构象的影响。通过疏水性偶极预测了蛋白质的吸附取向，表明蛋白质在疏油界面上存在优先吸附取向。吸附的 HFBI 的构象保持良好，而随着油疏水性的增加，CALB 的吸附过程中会发生相对较大的构象变化。对蛋白质与油的吸附相互作用能的比较证实了油极性与蛋白质与油的相互作用强度之间的关系。此外，CGMD 模拟允许在更长的时间尺度上模拟蛋白质在油水界面上的吸附行为。
