Prions Mutate and Adapt to Host Environment

[Moontanman]

Prions Mutate and Adapt to Host Environment

 

This light photomicrograph of brain tissue reveals the presence of typical amyloid plaques found in a case of variant Creutzfeldt-Jakob disease (vCJD). (Credit: Sherif Zaki; MD; PhD; Wun-Ju Shieh; MD; PhD; MPH)

 

ScienceDaily (Dec. 18, 2010) — Scientists from the Florida campus of The Scripps Research Institute have shown that prions, bits of infectious protein that can cause fatal neurodegenerative disease such as bovine spongiform encephalopathy (BSE) or "mad cow disease," have the ability to adapt to survive in a new host environment.

 

http://www.sciencedaily.com/releases/2010/12/101217083232.htm

[jimmydasaint]

Good find. I don't know much about prions except that they are proteins. However, from reading the article, it is clear that:

Mammalian cells normally produce cellular prion protein or PrPC. During infection, abnormal or misfolded protein -- known as PrPSc -- converts the normal host prion protein into its toxic form by changing its conformation or shape. The end-stage consists of large sheets (polymers) of these misfolded proteins, which causes massive tissue and cell damage

 

The conformation of the prions changes, depending on the cellular environment. I would contend, as a personal opinion that the prions change shape according to the environment as I would expect with any protein. The degree of hydrophilicity and hydrophobicity of the environment would change the overall shape of the prion.

 

Therefore, instead of seeing the process of cellular damage as an active process, e.g. from a viral infection, it looks as if the prions are passive and, IMHO, they should not be classified as infective agents.

Edited December 23, 2010 by jimmydasaint