Acetylenic Bond Layout Drives the Directional Assembly of Amyloid-like Peptides on Graphyne: Implications for Biomedical Safety Applications of Graphyne

Graphyne, a newly discovered carbon nanomaterial, has received increasing attention as a potential biomedical material. Although beta-rich peptide scaffolds have been implicated in a range of neurodegenerative diseases, the mechanisms by which toxic peptides assemble and mediate neuropathic effects remain poorly understood. Modeling the interaction between graphyne and beta-rich peptide scaffolds is crucial for understanding nanobiological effects or potential nanotoxicity and the safe design of graphyne as a nanomedicine material. Herein, we investigate the potential effects of graphyne on the assembly of A beta(33-42) peptides by molecular dynamics (MD) simulations. The A beta(33-42) peptide is considered to be the primary assembling core in the natural abnormal assembly of amyloid beta (A beta) proteins. The results show that A beta(33-42) strands are easily adsorbed to the graphyne surface and spontaneously aggregate into a well-structured beta-chain-like monolayer assembly through chain straightening, nucleation, and assembly processes in turn. The sp(1) and sp(2) hybrid orbitals in the carbon electronic structure of graphyne dominate the alignment of A beta(33-42) strands along the C C bonds with a specific "armchair" direction. Our findings deepen the understanding of the interaction between graphyne and biological macromolecules and provide implications for biomedical applications of graphyne.