Figure 4

SOD1 protein levels and dismutase activity are unchanged upon exposure.

(A, B) Total lysates from spinal cords of SOD^G85R (A), SOD1^G93A (B) and human SOD1^WT (wt n.ex.) mice were separated by SDS-PAGE and transferred on nitrocellulose membrane. SOD1 and tubulin were detected with specific antibodies by consecutive incubation on the same membrane (Supplemental Fig. 12). Bands of SOD1^G93A and human SOD1^WT run similar on the gels whereas SOD^G85R runs below human SOD1^WT and SOD1^G93A. The densitometric analysis is shown in the corresponding lower panels. Data were normalized to SOD1 levels of non-exposed mice overexpressing SOD1^WT (wt n.ex.) (mean +/−SEM, n = 5; t-test). (C) Extracts from spinal cords of mutant SOD1 mice at endstage of disease and non-exposed age-matched SOD1^WT mice (wt n.ex.) and purified human SOD1 (“C”) were separated on native PAGE gels. Dismutase activity was determined by zymography. The bright bands represent areas of dismutase activity. SOD1 and tubulin protein levels were controlled by standard Western blot analysis by consecutive incubation of the respective antibodies on the same membrane (lower panel). (D) Dismutase activity was quantitatively determined relative to the total protein amount by a WST-assay and compared to non-exposed age matched SOD1^WT mice and nontransgenic littermates (ntg. n.ex.) (mean +/−SEM; n = 4 for mutant mice; n = 3 for controls; t-test, n.s. not sigificant).