Below are some links about the work by Dr. Susan Lindquist from the Whitehead Institute and MIT, Professor of Biology. Dr. Lindquist has been able to elucidate the regions of prions which cause conformational changes which lead to amlyoid fiber formation and disease.
Scientist's Identify Prion's InfectiousSecret
Whitehead Intstitute for Biomedical Research Article
Prion Infectivity Pinpointed
Technology Review Article