Fig. 1.

Protein oxidation in human cortex and cerebellum. (A) Cortical and (B) cerebellar tissue samples from three non-demented individuals (Hu1–Hu3) and three Alzheimer's disease patients (Hu4–Hu6) were separated by centrifugation into cytoplasmic (C) and membrane (M) fractions and analyzed by derivatization-Western blotting using an anti-DNP antibody. The numbers in the margin indicate molecular weights (kDa). Parallel blots were probed for the membrane marker Na⁺/K⁺-ATPase (ATP1A1) and the cytoplasmic marker superoxide dismutase (SOD1). The bar graphs represent a quantification of the anti-DNP immunoreactivity. In both cortex and cerebellum, membrane proteins were significantly more oxidized than cytoplasmic proteins (upper panels: p<0.001 for cortex, p=0.003 for cerebellum by two-way ANOVA; n=6 for each tissue). Significance levels obtained by post-hoc analysis for the non-demented and Alzheimer's disease subgroups are given in the figure (lower panels).