http://www.pnas.org/content/99/6/3563.full.pdf

Structural studies of the scrapie prion protein by
electron crystallography

Holger Wille*†, Melissa D. Michelitsch‡, Vincent Gue´nebaut§¶

, Surachai Supattapone*†**, Ana Serban*,
Fred E. Cohen*‡§††, David A. Agard§¶, and Stanley B. Prusiner*†§‡‡

*Institute for Neurodegenerative Diseases, Departments of †Neurology, ‡Cellular and Molecular Pharmacology, §Biochemistry and Biophysics, and ††Medicine, and ¶The Howard Hughes Medical Institute, University of California, San Francisco, CA 94143
Contributed by Stanley B. Prusiner, December 27, 2001
Because the insolubility of the scrapie prion protein (PrPSc) has
frustrated structural studies by x-ray crystallography or NMR

spectroscopy, we used electron crystallography to characterize the
structure of two infectious variants of the prion protein. Isomorphous
two-dimensional crystals of the N-terminally truncated PrPSc
(PrP 27-30) and a miniprion (PrPSc106) were identified by negative
stain electron microscopy. Image processing allowed the extraction
of limited structural information to 7 Ĺ resolution. By comparing
projection maps of PrP 27-30 and PrPSc106, we visualized the
36-residue internal deletion of the miniprion and localized the
N-linked sugars. The dimensions of the monomer and the locations
of the deleted segment and sugars were used as constraints in the
construction of models for PrPSc. Only models featuring parallel

-helices as the key element could satisfy the constraints. These
low-resolution projection maps and models have implications for
understanding prion propagation and the pathogenesis of neurodegeneration.
electron microscopy image processing Nanogold labeling p

Structural studies of the scrapie prion protein by electron crystallography (autism) (als) (morgellons) and or (XMRV)