The Study Of The Self-assembly Of Two Amyloid-like Peptide At Water-solid Interfaces And In Bulk Solutions

In the past years the self-assembly of amyloid-like peptides has attracted increasing attentions, because it is highly related to neurodegenerative diseases and has a potential for serving as nanomaterial to fabricate novel and useful nanostructures. In this paper, we focused on the role of interfacial conditions in the self-assembly of an amyleid-like peptide. termed Pepll. It was found that, when dissolved in bulk solutions. Pepll formed into b-sheet structures and assembled into long filaments in several hours, as revealed by Thioflavin T fluorescence and transmission electron microscopy (TEM) morphology characterization, respectively. When the peptide solution was added onto a mica/HOPG substrate, peptide filaments with three preferred orientations with an angle of 60°to each other were formed immediately, as imaged in situ by atomic force microscopy (AFM). However, the kinetics in filament formation and the morphologies of the formed beta sheet either on HOPG and mica or in bulk solutions were quite different.These results indicate that the interfacial properties dramatically affect the peptide selfassembly process.We also choose another peptide which can formation (3-sheet in bolk water or on HOPG.it has 11 amino acid,the amino acid sequence bear similarity to Pepll, and named AC-Pll.We employed a AFM to monitor the growth of the AC-Pll.found it can foramtionβ-sheet on HOPG at tremendous speed,and all of the fibers were very regular.they show the same way with the Pepll on HOPG.