a School of Chemistry , University of Tehran , Tehran , Iran.
b Department of Polymer Science and Engineering , University of Bonab , Bonab , Iran.
J Biomol Struct Dyn. 2018 Nov;36(14):3623-3635. doi: 10.1080/07391102.2017.1396254. Epub 2017 Nov 7.
The interaction of ZnO nanoparticles with biological molecules such as proteins is one of the most important and challenging problems in molecular biology. Molecular dynamics (MD) simulations are useful technique for understating the mechanism of various interactions of proteins and nanoparticles. In the present work, the interaction mechanism of insulin with ZnO nanoparticles was studied. Simulation methods including MD and replica exchange molecular dynamics (REMD) and their conditions were surveyed. According to the results obtained by REMD simulation, it was found that insulin interacts with ZnO nanoparticle surface via its polar and charged amino acids. Unfolding insulin at ZnO nanoparticle surface, the terminal parts of its chains play the main role. Due to the linkage between chain of insulin and chain of disulfide bonds, opposite directional movements of N terminal part of chain A (toward nanoparticle surface) and N termini of chain B (toward solution) make insulin unfolding. In unfolding of insulin at this condition, its helix structures convert to random coils at terminal parts chains.
氧化锌纳米粒子与生物分子（如蛋白质）的相互作用是分子生物学中最重要和最具挑战性的问题之一。分子动力学（MD）模拟是理解蛋白质和纳米粒子各种相互作用机制的有用技术。在本工作中，研究了胰岛素与氧化锌纳米粒子的相互作用机制。考察了包括 MD 和 replica exchange molecular dynamics (REMD) 在内的模拟方法及其条件。根据 REMD 模拟的结果，发现胰岛素通过其极性和带电氨基酸与 ZnO 纳米粒子表面相互作用。在 ZnO 纳米粒子表面展开胰岛素时，其链的末端部分起主要作用。由于胰岛素链和二硫键链之间的连接，链 A 的 N 端部分（朝向纳米粒子表面）和链 B 的 N 端（朝向溶液）的相反方向运动使胰岛素展开。在这种条件下胰岛素的展开过程中，其螺旋结构在末端链部分转化为无规卷曲。
