Soltani Nima, Gholami Mohammad Reza
Department of Chemistry, Sharif University of Technology, Tehran, 11365-11155, Iran), Fax: (+98) 216 600 5718.
Chemphyschem. 2017 Mar 3;18(5):526-536. doi: 10.1002/cphc.201601000. Epub 2017 Jan 25.
Fibrillation of amyloid beta (Aβ) peptide is the hallmark of Alzheimer's disease. Given that interactions at the bio-nano interface affect the fibrillation tendency of this peptide, an understanding of the interactions at Aβ peptide-inorganic surfaces on the microscopic level can help to determine the possible neurotoxicity of nanoparticles. Here, the interactions between a fibril-forming peptide, Aβ , and (111) and (100) facets of gold and silver surfaces have been studied by conducting atomistic molecular dynamics simulations. The obtained results indicate that the adsorption onto gold and silver surfaces force the peptide into the β-sheet-rich conformations, which is prone to aggregation, suggesting a new mechanism for the acceleration of fibril formation upon interaction with nanoparticles. To quantify the β-sheet content for a single peptide, a new metrics based on the Ramachandran probability distribution is introduced.
淀粉样β（Aβ）肽的纤维化是阿尔茨海默病的标志。鉴于生物纳米界面的相互作用会影响该肽的纤维化趋势，在微观层面了解Aβ肽与无机表面之间的相互作用有助于确定纳米颗粒可能的神经毒性。在此，通过进行原子分子动力学模拟，研究了一种形成原纤维的肽Aβ与金和银表面的（111）和（100）晶面之间的相互作用。所得结果表明，吸附在金和银表面会迫使该肽形成富含β-折叠的构象，这种构象易于聚集，这表明了与纳米颗粒相互作用时加速原纤维形成的一种新机制。为了量化单个肽的β-折叠含量，引入了一种基于拉马钱德兰概率分布的新指标。
