Molecular dynamics simulations of peptide adsorption on self-assembled monolayers

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• 作者：Yun Xie ; Meifeng Liu ; Jian Zhou ; ^{jianzhou@scut.edu.cn}
• 关键词：Protein adsorption ; Molecular dynamics simulation ; Molecular simulation ; Biomaterial ; Anti-fouling ; Zwitterionic compound
• 刊名：Applied Surface Science
• 出版年：2012
• 期刊代码：6_01694332
• 类别：ms
• 出版时间：1 August, 2012
• 卷：258
• 期：20
• 页码：8153-8159
• 文件大小：915 K

摘要

All-atom molecular dynamics simulations are performed to investigate the neuromedin-B peptide adsorption on the self-assembled monolayers (SAMs) of SH(CH₂)₁₀N⁺(CH₃)₂CH₂CH(OH)CH₂SO₃^{鈭?/sup> (SBT), SH(CH₂)₁₀OH and SH(CH₂)₁₀CH₃. The force-distance profiles show that the surface resistance to peptide adsorption is mainly generated by the water molecules tightly bound to surfaces via hydrogen bonds (hydration water molecules); but surfaces themselves may also set an energy barrier for the approaching peptide. For the SBT-SAM, the surface first exerts a relatively high repulsive force and then a rather week attractive force on the approaching peptide; meanwhile the hydration water molecules exert a strong repulsive force on the peptide. Therefore, SBT-SAM has an excellent performance on resisting protein adsorption. For the OH-SAM and CH₃-SAM, surfaces show low or little energy barrier but strong affinity to the peptide; and the hydration water molecules apply merely a repulsive force within a much narrower range and with lower intensity compared with the case for the SBT-SAM. The analysis of structural and dynamical properties of the peptide, surface and water indicates that possible factors contributing to surface resistance include the hydrogen-bond formation capability of surfaces, mobility of water molecules near surfaces, surface packing density and chain flexibility of SAMs. There are a large number of hydrogen bonds formed between the hydration water molecules and the functional groups of the SBT-SAM, which greatly lowers the mobility of water molecules near the surface. This tightly-bound water layer effectively reduces the direct contact between the surface and the peptide. Furthermore, the SBT-SAM also has a high flexibility and a low surface packing density, which allows water molecules to penetrate into the surface to form tightly-bound networks and therefore reduces the affinity between the peptide and the surface. The results show that the protein-resistant properties of the SAMs are in the decreasing order of SBT-SAM > OH-SAM > CH₃-SAM, which provide mechanistic explanation on SBT materials鈥?excellent anti-fouling performance.}