Molecular Mechanism of Surface-Assisted Epitaxial Self-Assembly of Amyloid-like Peptides
Molecular Mechanism of Surface-Assisted Epitaxial Self-Assembly of Amyloid-like Peptides
复制标题
类淀粉肽表面辅助外延自组装的分子机制
DOI：
10.1021/nn303740j
复制
发表时间：
2012-10-01
期刊：
影响因子：
17.1
通讯作者：
Zhou, Ruhong
中科院分区：
文献类型：
--
作者：
Kang, Seung-gu;Li, Hai;Zhou, Ruhong
用原位原子力显微镜（AFM）观察到淀粉样肽（NH 2-VGGAVVAV-COHN 2）在云母表面上的令人惊讶的“直立”纤维状构象（具有类似于2.6 nm的高度），这与其在HOPG表面上的“平坦”构象（具有类似于0.9 nm的小得多的高度）非常不同。我们的全原子分子动力学（MD）模拟表明，它是强静电相互作用之间的肽的N-末端和云母表面，导致在云母上的直立构象和高度有序的β-链结构，具有2.5 +/- 0.1 nm的高度，与AFM实验一致。同样，我们的MD模拟表明，由于与HOPG的有利的疏水相互作用，相同的肽在HOPG表面上采用平坦构象。我们的模拟还表明，在云母中发现的外延图案优先控制的各向异性结合位点与固有的晶体晶胞的基础基板commer surate。
A surprising "upright" fibrilar conformation (with a height of similar to 2.6 nm) was observed with in situ atomic force microscopy (AFM) for an amyloid-like peptide (NH2-VGGAVVAV-COHN2) on mica surface, which is very different from its "flat" conformation (with a much smaller height of similar to 0.9 nm) on the HOPG surface. Our all-atom molecular dynamics (MD) simulations reveal that it is the strong electrostatic interactions between the N-terminus of the peptide and the mica surface that result in an upright conformation and a highly ordered beta-stranded structure on mica, with a height of 2.5 +/- 0.1 nm, consistent with the AFM experiment. Similarly, our MD simulations show that the same peptides adopt a flat conformation on HOPG surfaces due to the favorable hydrophobic interactions with HOPG. Our simulations also indicate that epitaxial patterns found in mica are preferentially controlled by anisotropic binding sites commer surate with the inherent crystallographic unit cell of the basal substrate.