Fig. 6: IM-MS identifies a population of degradation products in selected mutants.
From: Oligomerization, trans-reduction, and instability of mutant NOTCH3 in inherited vascular dementia
IM-MS plots from two experimental replicates demonstrated the presence of an entity appearing at 100 V for R90C, C49Y, and R75P mutant proteins (a–e, green circle). Investigation of WT and R141C protein failed to qualitatively identify this population. Further analysis of the C49Y mutant protein revealed an approximate mass of 55 kDa, smaller than the theoretical 86 kDa size of the purified Fc-fusion proteins. This degradation product was absent at lower voltages for all constructs (Fig. S6). Quantification of degradation product intensity relative to intact construct calculations is displayed in (f). By extracting the IM region of 22–25 (a, pink bar) both the degradation product and intact NOTCH3 intensities were extracted. Increased amounts of degradation product were observed in the R90C, C49Y, R75P, and R141C mutants (f). The ratio of degradation product to intact NOTCH3 was lowest for WT protein.
