Prions: Difference between revisions

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'''Prions '''have these characteristics:  
'''Prions '''have these characteristics:  


1.) "The transmissible agent consists of aggregated forms of a specific protein" <ref>J. M. Berg et al. (2007) p 53, Biochemistry, Sixth edition, New York, W.H. Freeman and Company</ref>.  
#&nbsp;"The transmissible agent consists of aggregated forms of a specific protein" <ref>J. M. Berg et al. (2007) p 53, Biochemistry, Sixth edition, New York, W.H. Freeman and Company</ref>.
#These [[Protein|protein]] aggregates cannot be degraded by the agents that degrade most other proteins <ref>J. M. Berg et al. (2007) p 53, Biochemistry, Sixth edition, New York, W.H. Freeman and Company</ref>.
#"The protein is largely or completely derived from a cellular protein called PrP, that is normally present in the brain" <ref>J. M. Berg et al. (2007) p 53, Biochemistry, Sixth edition, New York, W.H. Freeman and Company</ref>.


2.) These [[Protein|protein]] aggregates cannot be degraded by the agents that degrade most other proteins <ref>J. M. Berg et al. (2007) p 53, Biochemistry, Sixth edition, New York, W.H. Freeman and Company</ref>.
So an aggregated form of a protein (that is already present in the brain) is the infectious agent in prion diseases <ref>J. M. Berg et al. (2007) p 54, Biochemistry, Sixth edition, New York, W.H. Freeman and Company</ref>.  
 
3.) "The protein is largely or completely derived from a cellular protein called PrP, that is normally present in the brain" <ref>J. M. Berg et al. (2007) p 53, Biochemistry, Sixth edition, New York, W.H. Freeman and Company</ref>.
 
So an aggregated form of a protein (that is already present in the brain) is the infectious agent in prion diseases <ref>J. M. Berg et al. (2007) p 54, Biochemistry, Sixth edition, New York, W.H. Freeman and Company</ref>.


The pathalogic mechanism of prions is often associated with structural change. Exogenous prions cause the endogenous host proteins to undergo a structural change, rendering them functionless or harmful.  
The pathalogic mechanism of prions is often associated with structural change. Exogenous prions cause the endogenous host proteins to undergo a structural change, rendering them functionless or harmful.  

Revision as of 05:17, 18 October 2013

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 [5].

The pathalogic mechanism of prions is often associated with structural change. Exogenous prions cause the endogenous host proteins to undergo a structural change, rendering them functionless or harmful.

References

  1. ↑ J. M. Berg et al. (2007) p 53, Biochemistry, Sixth edition, New York, W.H. Freeman and Company
  2. ↑ J. M. Berg et al. (2007) p 53, Biochemistry, Sixth edition, New York, W.H. Freeman and Company
  3. ↑ J. M. Berg et al. (2007) p 53, Biochemistry, Sixth edition, New York, W.H. Freeman and Company
  4. ↑ J. M. Berg et al. (2007) p 53, Biochemistry, Sixth edition, New York, W.H. Freeman and Company
  5. ↑ J. M. Berg et al. (2007) p 54, Biochemistry, Sixth edition, New York, W.H. Freeman and Company
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