Prion

For the bird, see Prion (bird). For the protein, see PrP.

Prions are misfolded proteins with the ability to transmit their misfolded shape onto normal variants of the same protein. They characterize several fatal and transmissible neurodegenerative diseases in humans and many other animals. It is not known what causes the normal protein to misfold, but the abnormal three-dimensional structure is suspected of conferring infectious properties, collapsing nearby protein molecules into the same shape. The word prion derives from "proteinaceous infectious particle". Prion forms of PrP are responsible for transmissible spongiform encephalopathies, and prion forms of amyloid-beta and tau proteins cause Alzheimer's disease. It is possible that Lewy body dementia is caused by prions.

The word prion, coined in 1982 by Stanley B. Prusiner, is a portmanteau derived from protein and infection, hence prion, and is short for "proteinaceous infectious particle", in reference to its ability to self-propagate and transmit its conformation to other proteins. Its main pronunciation is /ˈpriːɒn/, although /ˈpraɪɒn/, as the homographic name of the Prion (bird) (prions or whalebirds) is pronounced, is also heard. In his 1982 paper introducing the term, Prusiner specified that it be "pronounced pree-on."

Prions and nanoplastics

Prion misfolding can be triggered by nanoplastics. They can cross the blood-brain barrier and interact with proteins. Nanoplastics are prone to interact with proteins, and this interaction fundamentally changes the crucial secondary structure of these biomolecules. This combined with a sporadic tertiary misfolding causes PrPc to misfold into PrPSc, and cause a transmissible spongiform encephalopathy disease.

References

https://www.hopkinsmedicine.org/health/conditions-and-diseases/prion-diseases

http://www.prionalliance.org/2013/12/02/what-are-human-prion-diseases/

https://www.nature.com/articles/s41598-019-52495-w