Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, Canada.
PLoS One. 2011;6(10):e25954. doi: 10.1371/journal.pone.0025954. Epub 2011 Oct 10.
Using atomic force microscopy (AFM) we investigated the interaction of amyloid beta (Aβ) peptide with chemically modified surfaces in order to better understand the mechanism of amyloid toxicity, which involves interaction of amyloid with cell membrane surfaces. We compared the structure and density of Aβ fibrils on positively and negatively charged as well as hydrophobic chemically-modified surfaces at physiologically relevant conditions. We report that due to the complex distribution of charge and hydrophobicity amyloid oligomers bind to all types of surfaces investigated (CH₃, COOH, and NH₂) although the charge and hydrophobicity of surfaces affected the structure and size of amyloid deposits as well as surface coverage. Hydrophobic surfaces promote formation of spherical amorphous clusters, while charged surfaces promote protofibril formation. We used the nonlinear Poisson-Boltzmann equation (PBE) approach to analyze the electrostatic interactions of amyloid monomers and oligomers with modified surfaces to complement our AFM data.
使用原子力显微镜（AFM），我们研究了淀粉样β（Aβ）肽与化学修饰表面的相互作用，以便更好地了解淀粉样毒性的机制，其中涉及淀粉样与细胞膜表面的相互作用。我们比较了在生理相关条件下，带正电荷和负电荷以及疏水性化学修饰表面上 Aβ 原纤维的结构和密度。我们报告说，由于电荷和疏水性的复杂分布，淀粉样寡聚体与所有类型的表面（CH₃、COOH 和 NH₂）结合，尽管表面的电荷和疏水性会影响淀粉样沉积物的结构和大小以及表面覆盖率。疏水性表面促进形成球形无定形簇，而带电荷的表面促进原纤维的形成。我们使用非线性泊松-玻尔兹曼方程（PBE）方法来分析淀粉样单体和寡聚体与修饰表面的静电相互作用，以补充我们的 AFM 数据。
