FIG. 4.

PK digestion of ovine TSE samples. (A) Caudal medulla (CM) or cerebellum (Cer) samples from BSE (0392)-affected or scrapie (1276, CH1641, and SSBP1)-affected sheep, along with healthy controls (C1 and C2), were digested by the addition of 50 μg/ml PK for 1 h. (B) Caudal medulla (lane 1) or cerebellum (lanes 2 to 6) samples from scrapie-affected sheep (animals 1276 and 0284) were digested by the addition of 50 μg/ml PK for 1 h (lanes 1 and 6) or by the addition of 150 μg/ml thermolysin every hour for a total of 8 h. For thermolysin digestions, resulting PrP fragments after 1, 4, 6, and 8 h of digestion are shown in lanes 2 to 5, respectively. (C) Cerebellum samples from scrapie-affected sheep (animals 0284, 0456, 0615, and 0836), along with healthy controls (C3 and C4), were digested by the addition of 50 μg/ml PK for 1 h. For all lanes, digested brain homogenate was loaded at 3.3 μl of 10% (wt/vol) per lane, and PrP was detected on Western blots with monoclonal antibody P4 (B and C) or L42 (A). Molecular mass markers are indicated in kilodaltons.