Fig. 4.

False identification of a LMNB1 peptide as GRID2-derived peptide results in a wrong protein expression profile. A, MS/MS spectrum derived from a deamidated LMNB1 peptide (upper panel, deamidated amino acid highlighted in green) misidentified as an unmodified isobaric GRID2 peptide (lower panel). Fragment ions with water or ammonia loss are marked with '*'. B, Expression pattern of LMNB1 and GRID2 proteins (top) and GRID2-derived peptides (bottom) according to www.humanproteomemap.org. The deamidated LMNB1 peptide that was erroneously identified as unmodified GRID2 peptide is highlighted in red.