School of Mechanical Engineering, Shanghai Jiao Tong University, 200240, People's Republic of China.
Nanotechnology. 2019 Apr 19;30(16):165701. doi: 10.1088/1361-6528/aafdd7. Epub 2019 Jan 11.
Protein translocation through nanopores is widely involved in molecular sensing and analyzing devices, whereby nanopore surface properties are crucial. However, fundamental understanding of how these properties affect protein motion inside nanopores remains lacking. In this work, we study the influence of nanopore surface wettability on voltage-driven protein translocation through nanopores with coarse-grained molecular dynamics simulations. The results show that the electrophoretic mobility of protein translocation increases as the contact angle of nanopore surface increases from 0° to 90°, but becomes almost constant as the contact angle is above 90°. This observation can be attributed to the variation of the friction coefficient of protein translocation through the nanopores with different nanopore contact angles. We further show that the interaction between nanopore and water, rather than that between the nanopore and protein, dominates the protein transport in nanopores. These findings provide new insights into protein translocation dynamics across nanopores and will be beneficial to the design of high-efficiency nanopore devices for single molecule protein sensing.
蛋白质通过纳米孔的转位广泛涉及分子传感和分析装置，其中纳米孔表面性质至关重要。然而，对于这些性质如何影响纳米孔内蛋白质运动的基本理解仍然缺乏。在这项工作中，我们使用粗粒度分子动力学模拟研究了纳米孔表面润湿性对电压驱动蛋白质通过纳米孔转位的影响。结果表明，随着纳米孔表面接触角从 0°增加到 90°，蛋白质转位的电泳迁移率增加，但当接触角超过 90°时，迁移率几乎保持不变。这一观察结果可以归因于通过具有不同纳米孔接触角的纳米孔转位的蛋白质的摩擦系数的变化。我们进一步表明，纳米孔与水之间的相互作用，而不是纳米孔与蛋白质之间的相互作用，主导了蛋白质在纳米孔中的传输。这些发现为纳米孔中蛋白质转位动力学提供了新的见解，并将有助于设计用于单分子蛋白质传感的高效纳米孔器件。
