CAMBRIDGE, Mass., May 9 -- Small peptide segments -- typically only 19 amino acids in length -- govern the switch from a normal protein to a self-perpetuating infectious prion, according to researchers here.
The same regions of the protein also govern whether the resulting prion can jump from one species to another, according to Susan Lindquist, Ph.D., of the Whitehead Institute for Biomedical Research.
The finding may shed new light on the development and transmission of prion-related disorders, such as bovine spongiform encephalopathy, the so-called mad-cow disease, Dr. Lindquist and Peter Tessier, Ph.D., reported online in Nature.
Bovine spongiform encephalopathy is a prion disease that affects cattle, but was apparently transmitted to humans in what is now called variant Creutzfeldt-Jakob disease. About one in a million people yearly is affected by the sporadic human form of Creutzfeldt-Jakob disease.