Inhibition of Lysozyme Fibrillation by Gold Nanorods and Nanoparticles

Amyloid fibrillation has been implicated in many neurodegenerations, dialysis-related amyloidosis, type II diabetes and more than 30 other amyloid-related diseases. Nanomaterials as potential inhibitors of amyloid fibrillation have attracted increasing interests. In the present study, the effects of gold nanorods (AuNRs) and nanoparticles (AuNPs) on amyloid fibrillation were investigated using hen egg white lysozyme (HEWL) as a model system. Our results indicated that AuNRs and AuNPs, especially AuNRs, present significant inhibitory effects on HEWL amyloid fibril formation during all the kinetic processes, from nucleation to elongation and equilibration stages. The stronger adsorption capacity of HEWL on AuNRs surface is the key mechanism of inhibition of HEWL amyloid fibrillation. Furthermore, AuNRs lead to more stable α-helix conformation and hydrophobic microenvironment of aromatic side groups in HEWL molecules, which facilitate the system to form small amorphous aggregates rather than oligomer, profibril or mature fibril.