FIG. 2.

Distribution of PrP^C and PrP^Sc after Sarkosyl extraction and centrifugation. Brain homogenates from the frontal cortex were prepared, and the supernatants and resuspended pellets were analyzed by CDI (A and B) and by Western blotting (C). (A) Distribution of PrP^C in supernatants and pellets. The amounts of PrP^C in the native state were determined by CDI, and the relative distribution of PrP^C between supernatants (gray bars) and pellets (black bars) was expressed as a percentage. (B) Comparison of D/N ratios among initial brain homogenates, supernatants, and pellets. TRF counts of denatured samples were divided by the counts in the corresponding native samples to give D/N ratios. White bars, brain homogenates; gray bars, supernatants; black bars, pellets. (A and B) Data shown represent the average values ± SD obtained for three different cases. The vCJD and sCJD cases were all of the PRNP codon 129 MM genotype, whereas the three non-CJD cases are MM, MV, and VV at PRNP codon 129, respectively. (C) The supernatants (Sup) and pellets (Pel) obtained after Sarkosyl extraction and centrifugation were treated with proteinase K, and the distribution of PrP^res was investigated by Western blotting, using MAb 3F4.