Fig. 3.

Assessment of the molecular mass of the wild-type RAIDD-DD:PIDD-DD complexes in solution by (a) SEC-MALS and (b) nanoESI-MS. In (a), the overall protein loading concentration was 1.5 mg/mL (magenta), 12 mg/mL (blue) and 24 mg/mL (red). In (b), native mass spectrum of 15 μM complex in 50 mM ammonium acetate buffer (pH 7.8) and ion series corresponding to RAIDD-DD:PIDD-DD species with stoichiometries 5:5, 6:5 and 7:5 are labeled with their charge states and indicated with blue circles, orange squares and purple triangles, respectively.