Fig. S7.

Stabilization of trimer correlates with cell death. The size of the SOD1 trimer population is proportional to the stability of that species in relation to other SOD1 species. We find that the stability of the SOD1 trimer is highly indicative of the incidence of cell death, with the stability of the mutants corresponding to cell death with a P value of 0.0476 (as calculated from the Fisher test) when all points are included. With removal of the outlier P62Y-SOD1, which mutation is extremely destabilizing at +62 kcal/mol (Fig. 3), the P value of the relation between SOD1 trimer stability and cell death becomes 0.001.