Abstract
Carbon nanospecies (CNPs) are of high interest in current research due to their many unique properties. They may be created by common processes, such as burning.
Therefore, they can become potential contaminants and may have a negative impact on human health and the biosphere. Moreover, they may also catalyze protein misfolding and subsequent amyloid formation, which is extremely hard to treat.
We investigated the influence of single-walled carbon nanotubes (SWNTs), fullerene (C-60), carbon quantum dots (CDs) and nanodiamonds (NDs) on amyloid formation. This research utilized the hen egg-white lysozyme (HEWL) as a model system.
Fibrils were detected by fluorescence of thioflavin-T (ThT) or Nile red (NR) and the results were confirmed by transmission electron microscopy (TEM). We have found that NDs promoted amyloid fibril formation at all concentrations.
The highest concentration of C-60 (250 μg ml(-1)) accelerated the process of fibrillation, while smaller concentrations (16 and 80 μg ml(-1)) prolonged the lag phase and were comparable to the control. SWNTs prolonged the lag phase of amyloid formation at all concentrations.
CDs efficiently terminated the growth of amyloid fibrils. When we compared the amyloidogenicity of all four types of CNPs, the following trend was apparent: NDs > control > C-60 > CDs > SWNTs.