Narrator: This is Science Today. Under normal conditions proteins fold up to form complex 3-D structures, but errors in protein folding can turn a normal healthy protein into an infectious agent known as a prion. Jonathon Weissman, a professor of cellular and molecular biology at the University of California San Francisco explains how protein misfolding can result in disease.
Weissman: A prion is an infectious protein, and unlike a virus that people are more familiar with, where you have DNA and genes that encode the virus, Prions are infectious on the basis of their shape.
Narrator: Weissman's group has been studying prion shapes, and has been able to demonstrate that different shapes are responsible for different strains of prion disease, the same way mutations in viral DNA cause different viral strains.
Weissman: These differences are encoded in the conformation of the prion, so that the same protein can misfold not only into an infectious form, a prion form, but in more than one type of infectious form.
Narrator: For Science Today, I'm Larissa Branin.