Ti_(3)C_(2)Tx MXene抗蛋白质吸附的分子模拟

Molecular simulation on anti-protein adsorption of Ti_(3)C_(2)Tx MXene

为阐明Ti_(3)C_(2)Tx MXene抗蛋白质的吸附机理,以分子动力学模拟为手段,设计了常见的几种蛋白质(β2微球蛋白、人血清蛋白(HSA)、牛血清蛋白(BSA)和溶菌酶)在水相里的动力学行为,作为蛋白质吸附模型参考系,系统地探究了Ti_(3)C_(2)O_(2)、Ti_(3)C_(2)(COOH)(OH)_(3)、Ti_(3)C_(2)(NH_(2))_(2)、Ti_(3)C_(2)(COOH)_(2)和Ti_(3)C_(2)(OH)_(2)MXene等5种表面官能团性质不同的Ti_(3)C_(2)Tx MXene对蛋白质构象的影响。结果表明:将参考系和上述5种Ti_(3)C_(2)Tx MXene表面的均方根位移和均方根波动进行比较,发现偏差幅度均在0.5 nm以内,说明这些蛋白质在Ti_(3)C_(2)Tx MXene的表面保留着天然构象,其中,Ti_(3)C_(2)(OH)_(2)MXene和Ti_(3)C_(2)(COOH)2 MXene因其亲水性最好,对蛋白质形变的影响最小;模拟过程中牛血清蛋白和Ti_(3)C_(2)O_(2)的质心距离始终保持恒定(3.5 nm),Ti_(3)C_(2)O_(2)/PVDF膜的BSA吸附量从纯PVDF膜的65μg/cm^(2)降低到28μg/cm^(2),说明Ti_(3)C_(2)Tx MXene具有显著的抗蛋白吸附特性;此外,模拟结果还从原子水平展示了抗蛋白质实验过程中Ti_(3)C_(2)Tx MXene通过水化层的空间位阻效应减少了对蛋白质的吸附。

To fully understand the anti-protein adsorption mechanism of Ti_(3)C_(2)Tx MXene,using molecular dynamics simulation as a means,the kinetic behaviors of proteins commonly used in biological field(β2-microglobulin,human serum protein(HSA),bovine serum protein(BSA)and lysozyme)in aqueous phase were designed and taken as reference,and the effects of Ti_(3)C_(2)O_(2),Ti_(3)C_(2)(COOH)(OH)_(3),Ti_(3)C_(2)(NH_(2))2,Ti_(3)C_(2)(COOH)_(2)and Ti_(3)C_(2)(OH)_(2)MXene on the conformation of proteins placed on their surfaces were systematically investigated.Simulation results show that:The comparison of the root mean square displacement and root mean square fluctuation between the reference and the surface of Ti_(3)C_(2)Tx MXene shows that both the deviation range are less than 0.5 nm,indicating that the protein can retain the natural conformation on the surface of Ti_(3)C_(2)Tx MXene.Among them,Ti_(3)C_(2)(OH)_(2)MXene and Ti_(3)C_(2)(COOH)_(2)MXene have the least influence on protein deformation due to the best hydrophilicity.Meanwhile,the centroid distance between bovine serum protein and Ti_(3)C_(2)O_(2)remains constant(3.5 nm)in the simulation process.Compared with pure PVDF membrane,the BSA adsorption capacity of Ti_(3)C_(2)O_(2)/PVDF membrane decreases from 65μg/cm^(2)to 28μg/cm^(2),indicating that Ti_(3)C_(2)Tx MXene has a significant anti-protein adsorption property.In addition,the simulation results also demonstrate at the atomic level that Ti_(3)C_(2)Tx MXene reduces protein adsorption through the steric hindrance effect of the hydration layer during the anti-protein experiment.