Enhanced separation and characterization of deamidated peptides with RP-ERLIC-based multidimensional chromatography coupled with tandem mass spectrometry

摘要: Deamidation of asparaginyl residues in proteins produces a mixture asparaginyl, n-aspartyl, and isoaspartyl residues, which affects the proteins’ structure, function, stability. Thus, it is important to identify quantify products evaluate effects biological systems. It still challenging task distinguish between n-Asp isoAsp deamidation proteome-wide analysis because their similar physicochemical properties. The quantification isomeric deamidated peptides also rather difficult coelution/poor separation reverse-phase liquid chromatography (RPLC). We here propose RP-ERLIC–MS/MS approach for separating quantifying on scale three related same peptide. key method use RPLC first dimensional ERLIC (electrostatic repulsion–hydrophilic interaction chromatography) second, with direct online coupling tandem MS. coeluti...