National Center for Nanoscience and Technology, Beijing, 100190, China.
Nanoscale. 2011 Apr;3(4):1592-9. doi: 10.1039/c0nr00782j. Epub 2011 Jan 31.
In this work, the binding modes of typical labeling molecules (thioflavin T (ThT), Congo red (CR) and copper(II) phthalocyanine tetrasulfonic acid tetrasodium salt (PcCu(SO(3)Na)(4))) on pentaalanine, which is a model peptide segment of amyloid peptides, have been resolved at the molecular level by using scanning tunneling microscopy (STM). In the STM images, ThT molecules are predominantly adsorbed parallel to the peptide strands and two binding modes could be identified. It was found that ThT molecules are preferentially binding on top of the peptide strand, and the mode of intercalated between neighboring peptides also exists. The parallel binding mode of CR molecules can be observed with pentaalanine peptides. Besides the binding modes of labeling molecules, the CR and PcCu(SO(3)Na)(4) display different adsorption affinity with the pentaalanine peptides. The results could be beneficial for obtaining molecular level insight of the interactions between labeling molecules and peptides.
在这项工作中，通过扫描隧道显微镜（STM）在分子水平上解析了典型标记分子（噻唑橙（ThT）、刚果红（CR）和铜（II）酞菁四磺酸四钠盐（PcCu（SO（3）Na）（4）））与五肽，即淀粉样肽的模型肽段的结合模式。在 STM 图像中，ThT 分子主要沿肽链平行吸附，并且可以识别两种结合模式。发现 ThT 分子优先结合在肽链的顶部，并且还存在相邻肽之间的嵌入模式。可以观察到 CR 分子与五肽的平行结合模式。除了标记分子的结合模式外，CR 和 PcCu(SO(3)Na)(4)与五肽的吸附亲和力也不同。这些结果有助于获得标记分子与肽之间相互作用的分子水平洞察力。
