Characterization of lipids in membrane vesicles from scrapie-infected hamster brain

Department of Veterinary Science, 1655 Linden Drive, University of Wisconsin-Madison, Madison, Wisconsin 53706, U.S.A. The lipid compositions of membrane vesicles from scrapie-infected and uninfected hamster brains were examined before and after detergent extraction. No differences were observed in polar lipids, glycolipids, gangliosides or neutral lipids examined by thin-layer chromatography. Analysis of detergent-extracted CsCl gradient fractions with high scrapie infectivity failed to reveal any glycerolphosphatides, although neutral lipids were demonstrated. The major neutral lipid associated with detergent-extracted membrane vesicles from both infected and uninfected brain was an unidentified lipid which was found to absorb u.v. radiation strongly from 250 to 300 nm wavelengths. Membrane neutral lipids that strongly absorb u.v. radiation at wavelengths normally used to inactivate viruses may protect a small nucleic acid essential for scrapie infectivity. Keywords: scrapie, hydrophobicity, u.v. inactivation, neutral lipid Received 18 September 1984; accepted 31 December 1984.