FIGURE 1.

PrP^Sc resistance to proteolytic degradation depends on NaCl concentration. PrP^Sc was purified from diseased brains in the absence or presence of 150 mm NaCl (see “Experimental Procedures”). A and B, equal amounts of both PrP^Sc samples were submitted to proteolytic treatment in different reactions using high (A) and low (B) concentration ranges of PK for 4 h at 37 °C with agitation at 600 rpm. Immunoblotting was conducted using 3F4 antibody. Molecular sizes of protein standards are indicated on the left of each panel.