AuNPs synthesised in situ from self-assembled peptide hydrogels modulating peptide secondary structure

The disease caused by amyloidosis is thought to be due to the toxicity of the hydrophobic groups exposed by the β-sheet structure among amyloid oligomers. The non-specific binding of nanomaterials to proteins and peptides may be able to modulate the β-sheet structure. In this work, we designed an amphipathic peptide Fmoc-FFCKK-OH based on the amyloid peptide FF sequence in order to evaluate nanomaterials as amyloid aggregation regulators. Au3+ was used to modulate peptide self-assembly to form hydrogels and to form gold nanoparticles (AuNPs) in situ under the reduction of –SH. We simplified the complex process of structural transformation of proteins and peptides by constructing a hydrogel model. The transformation and aggregation behaviour of the secondary structure of peptides on the surface of AuNPs over time was investigated. Circular dichroism (CD) and surface-enhanced Raman scattering (SERS) were used to observe the transition from random coil to β-sheet with some α-helix within Fmoc-FFCKK-OH. This work not only simplifies the complexity of the study but also contributes to the understanding of the role of AuNPs in the regulation of amyloid formation and provides a research basis for AuNPs as amyloid regulators.