Key Laboratory of Colloid and Interface Science, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, P. R. China.
J Phys Chem B. 2013 Sep 12;117(36):10475-83. doi: 10.1021/jp4044286. Epub 2013 Aug 29.
Modulation of the fibrillogenesis of amyloid peptide Aβ(1-40) with two Aβ-based peptide amphiphiles has been studied. Both peptide amphiphiles contain two alkyl chains but in different positions. The two alkyl chains of 2C12-Aβ(11-17) are attached to the same terminus of Aβ(11-17), while those of C12-Aβ(11-17)-C12 are separately attached to opposite termini of Aβ(11-17). Thioflavin T fluorescence spectroscopy shows that all the peptide amphiphiles promote the formation of the cross-β-sheet structure of Aβ(1-40) and the aggregation of Aβ(1-40), while 2C12-Aβ(11-17) does this more efficiently. The atom force microscopy images indicate that the modulations of these two peptide amphiphiles on the Aβ(1-40) aggregation experience two distinct pathways. 2C12-Aβ(11-17) leads to amorphous aggregates, whereas C12-Aβ(11-17)-C12 generates short rodlike fibrils. However, Fourier transform infrared spectroscopy suggests that the amorphous aggregates and rodlike fibrils display similar secondary structures. This work suggests that the aggregation ability and the aggregate structures of the peptide amphiphiles significantly affect their interactions with Aβ(1-40) and lead to different morphologies of the Aβ(1-40) aggregates.
两种基于 Aβ 的肽两亲物对淀粉样肽 Aβ(1-40)的原纤维形成进行了调制。两种肽两亲物都含有两条烷基链，但位置不同。2C12-Aβ(11-17)的两条烷基链连接到 Aβ(11-17)的同一末端，而 C12-Aβ(11-17)-C12 的两条烷基链分别连接到 Aβ(11-17)的相反末端。硫黄素 T 荧光光谱表明，所有肽两亲物都促进 Aβ(1-40)的交叉-β-折叠结构形成和 Aβ(1-40)的聚集，而 2C12-Aβ(11-17)的效率更高。原子力显微镜图像表明，这两种肽两亲物对 Aβ(1-40)聚集的调制经历了两条不同的途径。2C12-Aβ(11-17)导致无定形聚集体，而 C12-Aβ(11-17)-C12 生成短棒状原纤维。然而，傅里叶变换红外光谱表明，无定形聚集体和棒状原纤维显示出相似的二级结构。这项工作表明，肽两亲物的聚集能力和聚集结构显著影响它们与 Aβ(1-40)的相互作用，并导致 Aβ(1-40)聚集体呈现不同的形态。
