NR AHWU
AU Marsh,R.F.; Castle,B.E.; Dees,C.; Wade,W.F.
TI Equilibrium density gradient centrifugation of the scrapie agent in Nycodenz
QU Journal of General Virology 1984 Nov; 65(11): 1963-8
PT journal article
AB Plasma membrane-enriched preparations from scrapie-infected and healthy hamster brains were detergent-extracted, then separated by equilibrium density centrifugation in continuous Nycodenz gradients. The highest level of infectivity was always associated with the insoluble residue which sedimented through 40% Nycodenz. The degree of aggregation in these insoluble complexes varied depending upon treatment. Centrifugation in gradients containing 2 M- to 8 M-urea resulted in the formation of large insoluble aggregates which seemed to retain a high level of infectivity when measured by the method of incubation interval assay. However, measurement of infectivity in these same samples by endpoint titration of tenfold dilutions resulted in values a thousand times lower. These observations reinforce previous findings that scrapie infectivity exists as a macromolecular complex and, furthermore, they emphasize the necessity for using non-denaturing conditions for purification of the scrapie agent.
MH Animal; Brain/microbiology/ultrastructure; Cell Fractionation; Cell Membrane/ultrastructure; Centrifugation, Density Gradient/methods; Cricetulus; Detergents; Hamsters; Indicators and Reagents; Iohexol; Octoxynol; Polyethylene Glycols; Prions/*isolation & purification; Support, Non-U.S. Gov't; Support, U.S. Gov't, P.H.S.; Triiodobenzoic Acids
SP englisch
PO England