Nucleation of protein fibrillation by nanoparticles

Abstract

Nanoparticles present enormous surface areas and are found to enhance the rate of protein fibrillation by decreasing the lag time for nucleation. Protein fibrillation is involved in many human diseases, including Alzheimer's, Creutzfeld-Jacob disease, and dialysis-related amyloidosis. Fibril formation occurs by nucleationdependent kinetics, wherein formation of a critical nucleus is the key rate-determining step, after which fibrillation proceeds rapidly. We show that nanoparticles (copolymer particles, cerium oxide particles, quantum dots, and carbon nanotubes) enhance the probability of appearance of a critical nucleus for nucleation of protein fibrils from human ␤2-microglobulin. The observed shorter lag (nucleation) phase depends on the amount and nature of particle surface. There is an exchange of protein between solution and nanoparticle surface, and ␤2-microglobulin forms multiple layers on the particle surface, providing a locally increased protein concentration promoting oligomer formation. This and the shortened lag phase suggest a mechanism involving surface-assisted nucleation that may increase the risk for toxic cluster and amyloid formation. It also opens the door to new routes for the controlled self-assembly of proteins and peptides into novel nanomaterials.amyloid ͉ nanotoxicology ͉ surface-assisted nucleation

Quantum dots induce heat shock-related cytotoxicity at intracellular environment

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Nanoparticle accumulation and transcytosis in brain endothelial cell layers

“…[17][18][19][20][21][22] It is also known that nanoparticles can affect protein fibrillation rates. 23 At the same time, these observations have also opened unique possibilities for using nanoparticles to understand transcytosis and gain access to the CNS.…”

Collagen gel formation in the presence of a carbon nanobrush

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