NR AMOT
AU Wille,H.; Prusiner,S.B.
TI Ultrastructural studies on scrapie prion protein crystals obtained from reverse micellar solutions
QU Biophysical Journal 1999 Feb; 76(2): 1048-62
PT journal article
AB The structural transition from the cellular prion protein (PrPc) that is rich in alpha-helices to the pathological form (PrPsc) that has a high beta-sheet content seems to be the fundamental event underlying the prion diseases. Determination of the structure of PrPsc and the N-terminally truncated PrP 27-30 has been complicated by their insolubility. Here we report the solubilization of PrP 27-30 through a system of reverse micelles that yields monomeric and dimeric PrP. Although solubilization of PrP 27-30 was not accompanied by any recognizable change in secondary structure as measured by FTIR spectroscopy, it did result in a loss of prion infectivity. The formation of small two- and three-dimensional crystals upon exposure to uranyl salts argues that soluble PrP 27-30 possesses considerable tertiary structure. The crystals of PrP 27-30 grown from reverse micellar solutions suggest a novel crystallization mechanism that might be applicable for other membrane proteins. A variety of different crystal lattices diffracted up to 1.85 nm by electron microscopy. Despite the lack of measurable biological activity, the structure of PrP 27-30 in these crystals may provide insight into the structural transition that occurs during PrPsc formation.
MH Centrifugation, Density Gradient; Crystallization; Detergents/pharmacology; Endopeptidase K/metabolism; Liposomes/*metabolism; Membrane Proteins/isolation & purification; Microscopy, Electron; Octanes/metabolism; PrP 27-30 Protein/pathogenicity/*ultrastructure; PrPsc Proteins/*ultrastructure; Protein Structure, Secondary/drug effects; Protein Structure, Tertiary; Scattering, Radiation; Solubility/drug effects; Solvents/pharmacology; Spectroscopy, Fourier Transform Infrared; Support, Non-U.S. Gov't; Support, U.S. Gov't, P.H.S.
AD Department of Neurology, University of California, San Francisco, California 94143 USA.
SP englisch
PO USA