疏水蛋白吸附碳纳米管的分子动力学模拟

Molecular Dynamics Simulation of Hydrophobin Proteins on the Surface of Single-walled Carbon Nanotubes

采用分子动力学方法模拟了水溶液中Ⅱ型疏水蛋白HFBI在单壁碳纳米管(SWNTs)表面的吸附过程,考察了3种不同的HFBI初始取向,并计算了结合自由能,从累计240 ns的模拟轨迹中得到了不同的吸附结构.结果表明,当HFBI完全通过疏水面与SWNTs作用时,其结合自由能最有利吸附,且吸附最稳定.另外,由于HFBI含有4个二硫键,因此吸附过程几乎不改变其二级结构.

Carbon nanotubes （CNTs） coated by hydrophobin proteins through noncovalent interactions were shown to be soluble and dispersed in water. However, the detail of the microscopic structure and underlying interaction mechanism is fragmentary. In the present work, atomistic molecular dynamics （MD） simulations have been conducted to elucidate the adsorption mechanism of hydrophobin HFBI on the surface of single walled carbon nanotubes （SWNTs） in an aqueous environment. Three initial orientations of HFBI towards SWNTs were taken into account, and the relative binding free energies were calculated. Different adsorption conformations were obtained from MD simulation trajectories with an aggregate time of 240 ns. The present re sults reveal that the adsorption mode, where the adsorption sites fully come from the hydrophobic patch of the protein, is the most energetically favored. Furthermore, the main secondary structures of protein are preserved in the entire course of adsorption due to four disulfide bonds.