Inhibition of lysozyme fibrillation by functional groups in graphene oxide quantum dots

(A)TEM image of lysozyme. (B) Chemical modification illustration of GOQDs. Images of lysozyme after incubation with (C) 20 μg/mL and (D) 40 μg/mL of GOQDs. Lysozyme aggregated to form amyloid fibrils. GOQDs were enriched with –OH and –COOH to evaluate the influence of the functional groups on amyloid inhibition. The results showed that the electrostatic interaction may play a dominate role comparing to hydrophobic interaction in our situation. • The interaction between graphene oxide and amyloid proteins was distinct depending on the physical and chemical properties of both amyloid and graphene oxide. • In this paper, Graphene oxide quantum dots were enriched with –OH and –COOH to evaluate the influence of the functional groups on amyloid inhibition. • We found that the electrostatic interaction may play a dominate role comparing to hydrophobic interaction in our situation. Graphene oxide quantum dots (GOQDs) were enriched with carboxyl and hydroxyl groups, respectively, to characterize their effect on modulating the assembly of lysozyme. The hydroxyl enriched GOQDs showed the strongest inhibition effect for the fibrillation of lysozyme, which may due to the enhanced electrostatic interactions to proteins.