FIG 3.

PrP aggregates accumulate in tg1020 muscle. (A) (Top) Immunoprecipitation using the PrP conformation-specific antibody 15B3 reveals abundant PrP aggregates in tg1020 skeletal muscle. (Bottom) The protein loaded for the IP contained similar amounts of PrP. Note that 4-fold-larger amounts of the WT sample were loaded. IB, immunoblot; POM1, anti-PrP antibody. (B and C) PrP in muscle and brain, respectively. Antibodies 15B3 and POM2 were used for nondenaturing and denaturing IP, respectively, of the insoluble PrP fraction obtained after ultracentrifugation. POM1 was used for detection by Western blotting. Lower panels show the PrP levels for each sample used for IP. (D) PrP in tg1020 muscle is more PK resistant than PrP in the muscle of tga20 or WT mice as analyzed by PrP ELISA (graphed values are normalized). Asterisks indicate significant differences (*, P ≤ 0.05) by Student's t test.