FIG 2.
GdnHCl-induced unfolding demonstrates a similar conformational stability of PrPSc aggregates across the spectrum of CJD prions. Brain homogenates were treated with increasing concentrations of GdnHCl and digested with PK, followed by SDS-PAGE and immunoblotting. Membranes were incubated with the primary antibody 3F4. (A) Representative immunoblots showing similar denaturation profiles among the seven CJD types analyzed. (B) Plots of GdnHCl-induced PrPSc unfolding for each sCJD type and vCJD. The y axis reports the percentage of folded PrPSc (e.g., percentage of PK-resistant PrPSc) relative to the untreated sample. Symbols represent data expressed as means ± standard deviations, and lines represent the sigmoid curves that best fit the data. (C) [GdnHCl]50 values for each CJD type, expressed as means ± standard deviations, indicating the GdnHCl molar concentration necessary to unfold 50% of untreated PrPSc. (D) Percentage of folded PrPSc at 2 M GdnHCl, expressed as means ± standard deviations.