Figure 4.

Identified Protein Modifications and Their Distribution on Nano-LC Elution Gradients.

LC elution profiles used in LTQ-Orbitrap (Velos) for the identification of MYRed peptides were “stretched” within 40 to 60% buffer B (0.1 FA and 5% ACN) to maximize high-hydrophobicity peptide resolution (red dotted line). The maximum MYRed peptides (red dots) were observed within the 12 to 22 min retention time subsequent to the main elution bulk of non-modified peptides (gray). Other frequently observed posttranslational modifications such as phosphorylation (green), pyroglutamylation (yellow), and N-terminal acetylation (blue) are indicated (A). The correlation between GRAVY hydrophobicity index and retention time for MYRed (red) or acetylated (blue) peptides is presented in (B).