FIG. 6.

Treatment of ScN2a cells with PPI. ScN2a cells were transfected transiently with the pSPOX expression vector encoding either the full-length MHM2 or the MHM2(Δ23–88,Δ141–221) sequence. Three days after transfection cells were incubated with either control medium or medium plus 150 μg of PPI generation 4.0 per ml for 4 h. Cells were then harvested and lysed as described in Materials and Methods. Minus symbols denote undigested control lysate, and plus symbols designate the pellet fraction of lysate subjected to limited proteolysis with 20 μg of proteinase K per ml for 1 h at 37°C, corresponding to a total protein/proteinase K ratio of 25:1. Units are apparent molecular sizes based on migration of protein standards in kilodaltons. Lane 1, MHM2 control; lane 2, MHM2 plus PPI; lane 3, PrP61 control; lane 4, PrP61 plus PPI.