Molecular Dynamics Simulations of Hen Egg White Lysozyme Adsorption at a Charged Solid Surface
Molecular Dynamics Simulations of Hen Egg White Lysozyme Adsorption at a Charged Solid Surface
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DOI：
10.1021/jp901521x
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发表时间：
2009-09-10
影响因子：
3.3
通讯作者：
Mulheran, Paul A.
中科院分区：
文献类型：
--
作者：
Kubiak, Karina;Mulheran, Paul A.
使用原子分子动力学研究了鸡蛋清溶菌酶 (HEWL) 在带负电的亲水表面上的吸附。在 pH 7 和离子强度 0.02 M (NaCl) 下进行的 6 个 20 ns 轨迹分析表明，HEWL 吸附需要构象改变，并且吸附后蛋白质会失去一些 α 螺旋含量。对一些不同初始方向的模拟表明，HEWL 蛋白质吸附在平坦表面上，蛋白质长轴与表面之间的角度约为 45 度。主要吸附位点位于HEWL表面的N,C端部分；主要作用由 Lys1、Arg5、Arg14 和 Arg128 发挥。没有发现相反方向的吸附。用 0.5 M 离子强度计算的另外两个 20 ns 轨迹表明，控制吸附的主要力量是蛋白质部分和表面之间的静电吸引力。位于由带电表面构建的立方体盒内的蛋白质获得的轨迹表明，平坦表面和非平坦表面的吸附模式是不同的，特别是，非平坦表面上的吸附需要三级结构改变和部分展开。观察到的趋势与实验和先前的计算研究一致。
Hen egg white lysozyme (HEWL) adsorption on negatively charged, hydrophilic surfaces has been investigated using atomistic molecular dynamics. Analysis of six 20 ns trajectories performed at pH 7 and ionic strength 0.02 M (NaCl) reveals that conformational alterations are required for HEWL adsorption, and that upon adsorption the protein loses some alpha-helical content, Simulations for a few different initial orientations show that the HEWL protein adsorbs on a flat surface with an angle between the protein long axis and the surface of about 45 degrees. The main adsorption site is located on the N,C-terminal part of the HEWL surface; the major role is played by Lys1, Arg5, Arg14, and Arg128. Adsorption is not found with contrary orientations. Two additional 20 ns trajectories calculated with 0.5 M ionic strength suggest that the main force governing adsorption is electrostatic attraction between parts of the protein and the surface. A trajectory obtained for the protein situated inside a cubic box built from the charged surfaces shows that the adsorption pattern is different for flat and nonflat surfaces, and in particular, adsorption on the nonflat surface requires tertiary structure alterations and partial unfolding. The observed trends are consistent with both experimental and previous computational studies.