Prions
Not all infectious diseases are transmitted by bacteria or viruses. Some neurological diseases, such as Creutzfeldt-Jaakob disease (CJD) or mad cow disease are in fact caused by agents called Prions, which are of similar size to viruses but are made up of only protein [1]
Prions have these characteristics:
1.) "The transmissible agent consists of aggregated forms of a specific protein" [2]
2.) These protein aggregates cannot be degraded by the agents that degrade most other proteins [3]
3.) "The protein is largely or completely derived from a cellular protein called PrP, that is normally present in the brain" [4]
So an aggregated form of a protein (that is already present in the brain) is the infectious agent in prion diseases [1]
References
- ↑ 1.0 1.1 J. M. Berg et. al (2007) p 53, Biochemistry, Sixth edition, New York, W.H. Freeman and Company Cite error: Invalid
<ref>tag; name "null" defined multiple times with different content - ↑ J. M. Berg et. al (2007) p 53, Biochemistry, Sixth edition, New York, W.H. Freeman and Company
- ↑ J. M. Berg et. al (2007) p 53, Biochemistry, Sixth edition, New York, W.H. Freeman and Company
- ↑ J. M. Berg et. al (2007) p 53, Biochemistry, Sixth edition, New York, W.H. Freeman and Company