α-溶血素的电流整流与离子选择性：粗粒化分子动力学模拟
Current rectification and ionic selectivity of alpha-hemolysin: Coarse-Grained Molecular Dynamics simulations
AI总结：
本研究利用MARTINI粗粒化分子动力学模拟α-溶血素纳米孔的离子输运，验证了电流不对称与阴离子选择性，并识别出关键带电氨基酸，提出微观解释。
摘要：
为了在分子水平上理解纳米孔实验的物理过程，迫切需要来自分子动力学的微观信息。粗粒化模型是经典全原子模型的良好替代方案，因为它们允许更长时间的模拟以及施加更接近实验值的较低电势。我们通过插入脂质双层的α-溶血素蛋白纳米孔进行了离子输运的粗粒化分子动力学模拟，周围环绕溶剂和离子。为此，我们使用了MARTINI粗粒化力场及其极化水溶剂（PW）。此外，通过向系统施加电场来模拟实验中的电势差。在本研究中，我们展示了十二个不同系统的1.5微秒长分子动力学模拟结果，其中不同的带电氨基酸被中和，每个系统在正负0.04 V/nm之间的九个不同电场下进行（总共约100次模拟）。我们能够观察到该孔的若干特定特征，即电流不对称性和阴离子选择性，与先前的研究和实验一致，并确定了导致这些电流行为的带电氨基酸，从而验证了我们研究纳米孔离子输运的粗粒化方法。我们还利用离子密度图提出了这些离子电流特征的微观解释。
英文摘要：
In order to understand the physical processes of nanopore experiments at the molecular level, microscopic information from molecular dynamics is greatly needed. Coarse-grained models are a good alternative to classical all-atom models since they allow longer simulations and application of lower electric potentials, closer to the experimental ones. We performed coarse-grained molecular dynamics of the ionic transport through the $α$-hemolysin protein nanopore, inserted into a lipid bilayer surrounded by solvent and ions. For this purpose, we used the MARTINI coarse-grained force field and its polarizable water solvent (PW). Moreover, the electric potential difference applied experimentally was mimicked by the application of an electric field to the system. We present, in this study, the results of 1.5 microsecond long-molecular dynamics simulations of twelve different systems for which different charged amino acids were neutralized, each of them in the presence of nine different electric fields ranging between +/- 0.04 V/nm (a total of around 100 simulations). We were able to observe several specific features of this pore, current asymmetry and anion selectivity, in agreement with previous studies and experiments, and identified the charged amino acids responsible for these current behaviors, therefore validating our coarse-grain approach to study ionic transport through nanopores. We also propose a microscopic explanation of these ionic current features using ionic density maps.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
