Figure 3.

In vitro glutathionylation of SOD1 also promotes dimer dissociation and formation of soluble non-native oligomers. (A) Deconvoluted mass spectra for full-length SOD1 (unenriched and treated with GSSG). Labeled masses correspond to the average masses obtained by deconvolution of spectra using ProMass for Xcalibur software. Mass shifts corresponding to the addition of one, two, three, and four glutathione adducts are shown at left. At right, spectra are expanded to show only the mass range corresponding to unmodified SOD1 and SOD1 containing a single glutathione modification. (B) SEC chromatograms showing oligomeric populations of apo-SOD1 incubated in the presence or absence of GSSG prior to demetalation, then immediately separated by SEC at 4 °C.