title: A designed beta-hairpin forming peptide undergoes a consecutive stepwise process for self-assembly into nanofibrils.
abstract: We used a de novo designed, beta-hairpin forming T1 peptide as a model to investigate the kinetics of peptide fibrogenesis by a combination of light scattering (LS), circular dichroism (CD), fluorescence, and atomic force microscopy (AFM). The results demonstrate that the T1 fibrogenesis undergoes a consecutive stepwise process, with a high degree of cooperation, presenting sigmoidal time-courses of the peptide aggregation, the subsequent conformational conversion of the backbone, and the peptide sidechains' rearrangement. We suggest that the conformational conversion was initiated after the peptide aggregates reach a dimensional size threshold, which could be a key step in the formation of beta-structural nuclei that catalyze the subsequent reactions. Furthermore, besides triggering the peptide aggregation, the interactions between the peptide sidechains predominately facilitate the regular alignment of the peptide molecules and the formation of a well-defined suprastructure. This work provides an insight of the hierarchical self-assembly of beta-hairpin forming peptides. It is helpful for designing beta-structural peptides for self-assembly into nanowires, which would have potential applications in the construction of nano-materials.
authors.affiliation: Biomed-X Center and College of Engineering, Peking University, and Single-molecule and Nanobiology Laboratory, Department of Biophysics, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.
authors.forename: Chong
authors.initials: C
authors.lastname: Wang
authors.forename: Yinlin
authors.initials: Y
authors.lastname: Sha
mesh_terms: D002942:Circular Dichroism; D007700:Kinetics; D008027:Light; D018625:Microscopy, Atomic Force; D008856:Microscopy, Fluorescence; D057139:Nanofibers / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D012542:Scattering, Radiation
chemical_list: D010455:Peptides