Hydrophobic Interaction Drives Surface-Assisted Epitaxial Assembly of Amyloid-like Peptides
Hydrophobic Interaction Drives Surface-Assisted Epitaxial Assembly of Amyloid-like Peptides
复制标题
疏水相互作用驱动淀粉样肽的表面辅助外延组装
DOI：
10.1021/ja310989u
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发表时间：
2013-02-27
影响因子：
15
通讯作者：
Zhou, Ruhong
中科院分区：
文献类型：
--
作者：
Kang, Seung-gu;Tien Huynh;Zhou, Ruhong
研究了GaV-9(NH3+-VGGAV-VAGV-CONH2)的外延纤维形成的分子机制，GaV-9是从淀粉样蛋白的共同序列中提取的一种淀粉样肽，它在云母上呈直立状，在高度定向的热解石墨(HOPG)上呈扁平状。我们的全原子分子动力学模拟表明，较强的静电相互作用导致云母上的“直立”构象，而疏水相互作用则有利于HOPG上的“平坦”构象。我们还表明，云母上的外延图案是由基片上各向异性结合位与GaV-9分子尺寸之间的晶格匹配所保证的，并伴随着一系列定义良好的β-链。此外，结合自由能表面表明，纵向组装生长主要是由云母沿较长的晶胞方向的疏水相互作用驱动的。这些发现为表面辅助分子组装提供了分子基础，这也可能对从头开始的纳米器件的设计有用。
The molecular mechanism of epitaxial fibril formation has been investigated for GAV-9 (NH3+-VGGAV-VAGV-CONH2), an amyloid-like peptide extracted from a consensus sequence of amyloidogenic proteins, which assembles with very different morphologies, "upright" on mica and "flat" on the highly oriented pyrolytic graphite (HOPG). Our all-atom molecular dynamics simulations reveal that the strong electrostatic interaction induces the "upright" conformation on mica, whereas the hydrophobic interaction favors the "flat" conformation on HOPG. We also show that the epitaxial pattern on mica is ensured by the lattice matching between the anisotropic binding sites of the basal substrate and the molecular dimension of GAV-9, accompanied with a long-range order of well-defined beta-strands. Furthermore, the binding free energy surfaces indicate that the longitudinal assembly growth is predominantly driven by the hydrophobic interaction along the longer crystallographic unit cell direction of mica. These findings provide a molecular basis for the surface-assisted molecular assembly, which might also be useful for the design of de novo nanodevices.