Graphene oxide sheets and quantum dots inhibit alpha-synuclein amyloid formation by different mechanisms
Journal article, 2020

Aggregation and amyloid formation of the 140-residue presynaptic and intrinsically disordered protein alpha-synuclein (alpha-syn) is a pathological hallmark of Parkinson's disease (PD). Understanding how alpha-syn forms amyloid fibrils, and investigations of agents that can prevent their formation is therefore important. We demonstrate herein that two types of graphene oxide nanoparticles (sheets and quantum dots) inhibit alpha-syn amyloid formation by different mechanisms mediatedviadifferential interactions with both monomers and fibrils. We have used thioflavin-T fluorescence assays and kinetic analysis, circular dichroism, dynamic light scattering, fluorescence spectroscopy and atomic force microscopy to asses the kinetic nature and efficiency of this inhibitory effect. We show that the two types of graphene oxide nanoparticles alter the morphology of alpha-syn fibrils, disrupting their interfilament assembly and the resulting aggregates therefore consist of single protofilaments. Our results further show that graphene oxide sheets reduce the aggregation rate of alpha-syn primarily by sequestering of monomers, thereby preventing primary nucleation and elongation. Graphene quantum dots, on the other hand, interact less avidly with both monomers and fibrils. Their aggregation inhibitory effect is primarily related to adsorption of aggregated species and reduction of secondary processes, and they can thus not fully prevent aggregation. This fine-tuned and differential effect of graphene nanoparticles on amyloid formation shows that rational design of these nanomaterials has great potential in engineering materials that interact with specific molecular events in the amyloid fibril formation process. The findings also provide new insight into the molecular interplay between amyloidogenic proteins and graphene-based nanomaterials in general, and opens up their potential use as agents to manipulate fibril formation.

Author

Marziyeh Ghaeidamini

Chalmers, Biology and Biological Engineering, Chemical Biology

David Bernson

Chalmers, Biology and Biological Engineering, Chemical Biology

Nima Sasanian

Chalmers, Biology and Biological Engineering, Chemical Biology

Ranjeet Kumar

Chalmers, Biology and Biological Engineering, Chemical Biology

Elin Esbjörner Winters

Chalmers, Biology and Biological Engineering, Chemical Biology

Nanoscale

2040-3364 (ISSN)

Vol. 12 37 19450-19460

Vad karaktäriserar en toxisk amyloid oligomer?

Swedish Research Council (VR), 2017-01-01 -- 2020-12-31.

Areas of Advance

Nanoscience and Nanotechnology (SO 2010-2017, EI 2018-)

Subject Categories

Physical Chemistry

Other Chemistry Topics

Biophysics

DOI

10.1039/d0nr05003b

PubMed

32959853

More information

Latest update

1/21/2021