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Experimental Scrapie in the Mouse: Electrophoretic and Sedimentation Properties of the Partially Purified Agent
Author(s) -
Prusiner Stanley B.,
Garfin David E.,
Cochran S. Patricia,
McKinley Michael P.,
Groth Darlene F.,
Hadlow William J.,
Race Richard E.,
Eklund Carl M.
Publication year - 1980
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1980.tb03693.x
Subject(s) - sodium dodecyl sulfate , percoll , sedimentation coefficient , chromatography , chemistry , electrophoresis , ultracentrifuge , gel electrophoresis , centrifugation , sodium , differential centrifugation , biochemistry , enzyme , organic chemistry
: Some biochemical and biophysical properties of the scrapie agent in a partially purified fraction P 5 from murine spleen are described in this communication. The agent was stable in the nonionic detergents Triton X‐100 and Nonidet P40 and stable in the nondenaturing, anionic detergents sodium cholate and sodium N ‐lauroyl sarcosinate. In contrast, sodium dodecyl sulfate (SDS) inactivated the agent at high concentrations (1% or >) when the detergent‐to‐protein ratio approached 1.5 g SDS/g protein. The agent was resistant to inactivation by nucleases and proteases, even in the presence of 0.1% SDS. A broad peak of infectivity was exhibited in modified colloidal silica (Percoll) density gradients. Maximal titers were found at a Percoll density of 1.10 g/cm 3 in the presence and absence of 0.05% SDS. Gel electrophoresis of the agent in the presence of 0.1% SDS resulted in inactivation of >95% of the agent loaded onto the gel. Free‐flow electrophoresis showed that >99% of the agent in fraction P 5 migrated toward the anode, but not as a discrete species. Sedimentation analysis of the agent in fraction P 5 in the presence of 1% lysolecithin showed that the agent has a sedimentation coefficient of <300S but >30S. Heating P 5 preparations caused the agent to associate with cellular elements and form aggregates with sedimentation coefficients >10,000S. Removal by differential centrifugation of the large forms of the agent produced upon heating permitted characterization of a discrete subpopulation of scrapie agent particles. Rate‐zonal sucrose gradient studies showed that >>95% of the infectivity in this subpopulation sedimented as uniform particles with a sedimentation coefficient of 240S.