Defects in Protein Provide the Molecular Basis for a Wide Range of Human
Despite the many processes that assist in protein folding, misfolding does occur.
In fact, protein misfolding is a substantial problem in all cells, and a quarter or
more of all polypeptides synthesized may be destroyed because they do not fold
correctly. In some cases, the misfolding causes or contributes to the development
of serious disease.
The Prion Diseases:
A misfolded brain protein seems to be the causative agent of several rare
degenerative brain diseases in mammals. Perhaps the best known of these is
mad cow disease, kuru, Creutzfeldt-Jakob in humans, Scrapie in sheep, and
chronic wasting disease in deer and elk. These diseases are also referred to as
spongiform encephalopathies because the diseased brain frequently becomes
riddled with holes. The diseases are fatal.
The infectious agent has been traced to a single protein, called prion protein
(PrP). Prion protei