The Membrane Location of Scrapie Infectivity

Abstract
Using 5''-nucleotidase and NADPH:cytochrome c reductase as respective enzyme markers for the plasma membrane and endoplasmic reticulum, a satisfactory separation of these 2 membrane fractions from a cell line (SMB) derived from a scrapie mouse brain has been achieved. The coincident distribution of scrapie infectivity and 5''-nucleotidase in various fractions isolated from these cells indicates that most of the scrapie infectivity present in this cell line is associated with the plasma membrane.