溶菌酶蛋白在聚合物防污膜表面的吸附

Lysozyme Protein Adsorbed on Antifouling Polymer Film Surface

采用分子动力学模拟方法比较了溶菌酶蛋白在两种典型聚合物防污材料聚乙二醇(PEG)和聚二甲基硅氧烷(PDMS)表面的吸附行为,在微观上探讨了聚合物膜表面性质对蛋白质吸附的影响.根据蛋白质与聚合物膜之间的相互作用、能量变化及表面水化层分子的动力学行为,解释了PEG防污涂层相对于PDMS表面具有更佳防污效果的原因:(1)相比PDMS涂层,蛋白质与PEG涂层的结合能量较低,使其结合更加疏松;(2)蛋白质吸附到材料表面要克服表面水化层分子引起的能障,PEG表面与水分子之间结合紧密,结合水难于脱附,造成蛋白质在其表面的吸附需要克服更高的能量,不利于蛋白质的吸附.

Molecular dynamics simulations were used to compare the adsorption behavior of lysozyme on two typical antifouling polymer materials： poly（ethylene） glycol （PEG） and poly（dimethylsiloxane） （PDMS）. The influence of the surface properties of the polymer films on protein adsorption is discussed at the microscale. Based on the interactions, energy changes between the protein and polymer films, and dynamical behavior of the hydration molecules near the polymer film, the reasons why the PEG antifouling coating has a better antifouling effect than the PDMS surface were determined as follows. （1） The lower binding energy between the protein and the PEG coating than between the protein and the PDMS coating makes the protein adsorb weaker on the PEG coating than on the PDMS coating. （2） The protein would adsorb on the film surface when overcoming the energy barrier caused by the hydration layer. Molecular water adsorbs on the PEG surface stronger than on the PDMS surface, and is difficult to desorb. Therefore, the protein needs to overcome a higher energy barrier to adsorb to the PEG surface than to the PDMS surface, and thus it is more difficult for protein to absorb on the PEG surface than on the PDMS surface.