Figure 1: Optimization of a SUMO remnant immunoaffinity purification strategy.

(a) Protein sequences of the endogenous ubiquitin, endogenous SUMO3 and SUMO3m. (b) Overview of the remnant immunoaffinity purification. Cell lysates are subjected to a NiNTA column to enrich SUMOylated proteins before tryptic digestion. Peptides containing the SUMO3m remnant are enriched using the anti-K-(NQTGG) antibody. Subsequent peptides are injected on a Tribrid Fusion. Peptide identification is performed using MaxQuant.