Non-electrostatic binding and self-association of amyloid beta-peptide on the surface of tightly packed phosphatidylcholine membranes.
Non-electrostatic binding and self-association of amyloid beta-peptide on the surface of tightly packed phosphatidylcholine membranes.
复制标题
淀粉样β-肽在紧密堆积的磷脂酰胆碱膜表面上的非静电结合和自缔合。
DOI：
10.1016/j.bbrc.2008.08.093
复制
发表时间：
2008
影响因子：
3.1
通讯作者：
H. Takeuchi
中科院分区：
文献类型：
--
作者：
Mayumi Yoda;T. Miura;H. Takeuchi
淀粉样β-肽（Aβ）的自缔合被认为是阿尔茨海默病发展的初始步骤，并且已知被带负电荷的脂质膜促进。我们用中性磷脂酰胆碱脂质研究了非静电Aβ-膜相互作用的可能性。荧光光谱和圆二色光谱清楚地表明，Aβ在层状凝胶相中结合到磷脂酰胆碱膜上，但在涟漪凝胶或液晶相中不结合，这表明层状凝胶相的紧密脂质堆积特性的重要性。Aβ-膜结合在低盐浓度和高盐浓度下均发生，确保了相互作用的非静电性质。膜结合Aβ分子呈现单体α螺旋或自缔合β折叠结构，具体取决于温度、肽/脂质比和盐浓度。紧密堆积的磷脂酰胆碱膜的平坦表面似乎是Aβ非静电结合和自缔合的平台。
Self-association of amyloid β-peptide (Aβ) is considered to be an initial step in the development of Alzheimer’s disease and is known to be promoted by negatively charged lipid membranes. We have examined the possibility of non-electrostatic Aβ–membrane interaction by using neutral phosphatidylcholine lipids. Fluorescence and circular dichroism spectra have clearly shown that Aβ binds to the phosphatidylcholine membrane in the lamellar gel phase but not in the ripple gel or liquid crystalline phase, indicating the importance of the tight lipid packing characteristic of the lamellar gel phase. The Aβ–membrane binding occurs at both low and high salt concentrations, ensuring the non-electrostatic nature of the interaction. The membrane-bound Aβ molecule takes a monomeric α-helical or self-associated β-sheet structure depending on the temperature, peptide/lipid ratio, and salt concentration. The flat surface of tightly packed phosphatidylcholine membranes appears to serve as a platform for non-electrostatic binding and self-association of Aβ.