title: Chiral effect at protein/graphene interface: a bioinspired perspective to understand amyloid formation.
abstract: Protein misfolding to form amyloid aggregates is the main cause of neurodegenerative diseases. While it has been widely acknowledged that amyloid formation in vivo is highly associated with molecular surfaces, particularly biological membranes, how their intrinsic features, for example, chirality, influence this process still remains unclear. Here we use cysteine enantiomer modified graphene oxide (GO) as a model to show that surface chirality strongly influences this process. We report that R-cysteine modification suppresses the adsorption, nucleation, and fiber elongation processes of Aβ(1-40) and thus largely inhibits amyloid fibril formation on the surface, while S-modification promotes these processes. And surface chirality also greatly influences the conformational transition of Aβ(1-40) from α-helix to β-sheet. More interestingly, we find that this effect is highly related to the distance between chiral moieties and GO surface, and inserting a spacer group of about 1-2 nm between them prevents the adsorption of Aβ(1-40) oligomers, which eliminates the chiral effect. Detailed study stresses the crucial roles of GO surface. It brings novel insights for better understanding the amyloidosis process on surface from a biomimetic perspective.
authors.affiliation: School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology , 122 Luoshi Road, Wuhan 430070, People's Republic of China.
authors.forename: Guangyan
authors.initials: G
authors.lastname: Qing
authors.forename: Shilong
authors.initials: S
authors.lastname: Zhao
authors.forename: Yüting
authors.initials: Y
authors.lastname: Xiong
authors.forename: Ziyu
authors.initials: Z
authors.lastname: Lv
authors.forename: Fenglei
authors.initials: F
authors.lastname: Jiang
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Mingxi
authors.initials: M
authors.lastname: Zhang
authors.forename: Taolei
authors.initials: T
authors.lastname: Sun
mesh_terms: D000327:Adsorption; D000682:Amyloid / Q000737:chemistry*; D016229:Amyloid beta-Peptides / Q000737:chemistry*; D003545:Cysteine / Q000031:analogs & derivatives*; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D010087:Oxides / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013499:Surface Properties
chemical_list: D000682:Amyloid; D016229:Amyloid beta-Peptides; D010087:Oxides; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); D006108:Graphite; D003545:Cysteine