Zhang Lan, Zhong Jian, Huang Lixin, Wang Lijun, Hong Yuankai, Sha Yinlin
Single-Molecule and Nanobiology Laboratory, Department of Biophysics, School of Basic Medical Sciences, Biomed-X Center, and Center for Protein Science, Peking University, Beijing 100083, China.
J Phys Chem B. 2008 Jul 31;112(30):8950-4. doi: 10.1021/jp802424h. Epub 2008 Jul 2.
Peptide self-assembly on substrates is currently an intensively studied topic that provides a promising strategy for fabrication of soft materials and is also important for revealing the surface chemistry of amyloidogenic proteins that aggregate on cell membranes. We investigated the fibrogenesis of a beta-sheet forming peptide Abeta(26-35) on supported lipid bilayers (SLBs) by in situ atomic force microscopy (AFM), circular dichroism (CD), and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The results show that the Abeta(26-35) nanofilaments' growth is oriented to a specific direction and formed a highly ordered, large-scale, parallel-oriented surface pattern on membranes. The parallel-oriented fibrogenesis of Abeta(26-35) was able to occur on different lipid membranes rather than on solid substrates. It implies that the parallel-oriented fibrogenesis was associated with the distinct properties of lipid membranes, such as the fluid nature of lipid molecules on membranes. The membrane fluidity may allow the peptide assemblies to float at the water-membrane interface and easily orient to an energetically favorable state. These results provide an insight into the surface chemistry of peptide self-assembly on lipid membranes and highlight a possible way to fabricate supramolecular architectures on the surface of soft materials.
肽在基底上的自组装是目前一个被深入研究的课题，它为软材料的制备提供了一种有前景的策略，对于揭示在细胞膜上聚集的淀粉样蛋白的表面化学性质也很重要。我们通过原位原子力显微镜（AFM）、圆二色性（CD）和衰减全反射傅里叶变换红外（ATR-FTIR）光谱研究了β-折叠形成肽Abeta(26 - 35)在支撑脂质双层（SLB）上的纤维化过程。结果表明，Abeta(26 - 35)纳米丝的生长沿特定方向取向，并在膜上形成了高度有序、大规模、平行取向的表面图案。Abeta(26 - 35)的平行取向纤维化能够在不同的脂质膜上发生，而不是在固体基底上。这意味着平行取向纤维化与脂质膜的独特性质有关，比如膜上脂质分子的流动性。膜的流动性可能使肽组装体在水 - 膜界面漂浮，并容易取向到能量有利的状态。这些结果为肽在脂质膜上的自组装表面化学提供了深入了解，并突出了在软材料表面构建超分子结构的一种可能方法。
