Adsorption of alpha-synuclein and inhibition of fibril formation by nanocellulose and gold-coated-nanocellulose

Interfering with the aggregation of the protein alpha-synuclein (aSyn) has been a topic of research for > 25 years, as this protein is found in pathognomonic protein aggregates in the brain of patients with Parkinson’s disease and related synucleinopathies. This study aimed to characterize the adsorption of aSyn and the inhibition of aSyn fibril formation by nanocellulose (NC) and NC coated with gold atoms (NCCGAs) using by both in silico and laboratory approaches. First, using the HDOCK server and Ascalaph designer software we assessed the possible molecular interaction of partial aSyn (36–55) and full length aSyn (1–140) when exposed to NC and NCCGAs. We then used acid hydrolysis to synthesize NC and then it reacted with HAuCl4 to generate NCCGAs. The adsorption of aSyn by NC and NCCGAs was analyzed at 280 nm and the inhibition of aSyn fibril formation was assessed using Thioflavin T. By comparing the docking results, we found that NCCGAs have more and better adsorption to partial/full length aSyn than NC. Also, molecular dynamics simulations showed that adsorbed partial/full length aSyn display stable interactions and that this increases over time. Experimentally, the adsorption of aSyn and the inhibition of aSyn fibril formation were observed upon exposure to NC or NCCGAs. Although both NC and NCCGAs adsorbed aSyn, NCCGAs had a higher capability (P > 0.05). The same pattern was observed for the inhibition of aSyn fibril formation.