Figure 4
From: A covalent peptide inhibitor of RGS4 identified in a focused one-bead, one compound library screen
MS analysis of RGS4 with and without 5nd pretreatment. RGS4Δ51N was cleaved from the MBP-His6 construct and subject to MALDI MS after pretreatment with DMSO (A) or 5nd (250 μM) (B). Both spectra show the region between 4,000 and 30,000 m/z and have the peak at 18158.8 or 18158.2 m/z for A and B, respectively, which corresponds to the cleaved RGS4Δ51N protein (black arrows). The spectrum in B also has a peak at 19158 m/z that corresponds to a peptide adduct (grey arrows). There is a very small peak at 20157.9 that may correspond to 2 peptides per RGS (grey arrows). The inset is a blow-up of the region between 17500 and 20500 m/z.