Separation of peptide isomers with variant modified sites by high-resolution differential ion mobility spectrometry.

ABSTRACT: Many proteins and proteolytic peptides incorporate the same post-translational modification (PTM) at different sites, creating multiple localization variants with different functions or activities that may coexist in cells. Current analytical methods based on liquid chromatography (LC) followed by tandem mass spectrometry (MS/MS) are challenged by such isomers that often coelute in LC and/or produce nonunique fragment ions. The application of ion mobility spectrometry (IMS) was explored, but success has been limited by insufficient resolution. We show that high-resolution differential ion mobility spectrometry (FAIMS) employing helium-rich gases can readily separate phosphopeptides with variant modification sites. Use of He/N(2) mixtures containing up to 74% He has allowed separating to >9

SUBMITTER: Shvartsburg AA 

PROVIDER: S-EPMC2973842 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature