Soft Matter Research Center and Department of Chemistry, Zhejiang University, Hangzhou 310027, PR China.
Soft Matter Research Center and Department of Chemistry, Zhejiang University, Hangzhou 310027, PR China.
Biomaterials. 2014 Feb;35(5):1771-8. doi: 10.1016/j.biomaterials.2013.11.041. Epub 2013 Nov 27.
In this work the encapsulation of an α-helical peptide in single carbon nanotubes (CNTs) with similar diameter and length but different geometry (armchair and zigzag) was investigated through molecular dynamics simulations and free energy calculations. Our simulation results showed that in vacuo it makes no evident difference whether the investigated peptide is encapsulated in armchair or zigzag CNTs; however, in aqueous solution the armchair CNT encapsulates the peptide remarkably easier than the zigzag CNT does. A detailed analysis revealed that the equilibrium conformation of the water molecules inside the CNTs with varying geometry mediates the peptide encapsulation. It suggests that the water molecules play an important role in regulating behaviors of biomolecules in bio-systems. Then the impact of the CNT geometry on the conformational changes of the confined peptide was studied. Analyses of secondary structures showed the α-helix of the peptide could be better maintained in the zigzag CNT.
在这项工作中，通过分子动力学模拟和自由能计算研究了具有相似直径和长度但几何形状不同（扶手椅型和锯齿型）的单根碳纳米管（CNT）对α-螺旋肽的封装。我们的模拟结果表明，在真空中，被研究的肽被封装在扶手椅型或锯齿型 CNT 中并没有明显的区别；然而，在水溶液中，扶手椅 CNT 比锯齿型 CNT 更容易封装肽。详细分析表明，具有不同几何形状的 CNT 内水分子的平衡构象调节了肽的封装。这表明水分子在调节生物系统中生物分子的行为方面起着重要作用。然后研究了 CNT 几何形状对受限肽构象变化的影响。二级结构分析表明，肽的α-螺旋在锯齿型 CNT 中能更好地保持。
