Wednesday, April 25, 2012

Misfolded Proteins

Proteins are present throughout our bodies and are involved in virtually every cell function.  Proteins enable movement by allowing muscle contraction, speed up chemical reactions, and defend against foreign cells.  Proteins are made up of a chain of compounds called amino acids, which interact with each other in a specific way causing the amino acid chain to fold.  The folding of a protein is essential for its function.  However if the protein isn't folded correctly, then they can be destructive to our bodies.  For instance, Huntington's disease, Alzheimer's disease, type 2 diabetes, sickle cell disease and prion disease are all proteopathies, or diseases caused by protein misfolding.

What if these incorrectly folded proteins were capable of replicating themselves to further damage the body?  Well prions do just that.  Prions are defined as infectious agents comprised of a misfolded protein.  Unlike other disease-causing agents like viruses and bacteria, prions contain no genetic material (DNA or RNA); however, they have the ability to convert properly folded proteins into incorrectly folded one like themselves.  The improperly folded proteins then accumulate in tissue causing tissue damage and cell death.  This chain reaction occurs in prion diseases like mad cow disease and its human counterpart, Creutzfeldt-Jakob disease (CJD), the degenerative neurological disorder.

Prion diseases have always been considered untreatable because it is difficult to target these misfolded protein because proteins are all throughout our bodies.  A recent study published in the Journal of Biological Chemistry this month found a way to inhibit their ability to produce more prions.  They used luminescent conjugated polymers (LCPs) to detect the presence of prions in mice brains.  However, they noticed that the number of prions, toxicity, and infectibility decreased in the process.  Most likely, the interaction with the LCP's stabilizes the prions, inhibiting their propagation.  However, LCP's contain many chemical subgroups.  When eight different subgroups were tested, all of them had significant decrease in the toxicity of the prions.

These results are the first that provide the possibility of treating prion diseases.  Also if the LCP's can interact with other misfolded proteins that cause other proteopathies, then the application of these results may be applied to other diseases, like Alzheimer's disease and Huntington's disease.    

Read more about this research here.


  1. I was just logging in to write a post about this same topic! It's so cool, although I'm not sure if I buy their hopes about an Alzheimer's treatment quite yet.

  2. Looks like its prion week around here...