Figure 5.

Intermolecular disulfide bonding is not universally required for the persistence of metastable non-native oligomers in vitro. (A) Apo-SOD1 oligomers generated by incubation for 1 week at 37 °C in 20 mM Tris and 150 mM NaCl at pH 7.4 were separated by SEC in the absence (black curves) of DTT and in the presence of 1 mM DTT following incubation at room temperature (red curves). Designations of oligomeric populations (D, M, O1, O2, O3, and V₀) correspond to those in Figure 2A, while M* denotes a species that that appears subsequent to DTT treatment and whose elution volume is consistent with an expanded monomer. (B) Quantification of oligomeric populations prior to DTT treatment and after room temperature incubation with 1 mM DTT for the indicated time periods. ON = overnight incubation.