Counterion Optimization Dramatically Improves Selectivity for Phosphopeptides and Glycopeptides in Electrostatic Repulsion-Hydrophilic Interaction Chromatography.

ABSTRACT: A well-hydrated counterion can selectively and dramatically increase retention of a charged analyte in hydrophilic interaction chromatography. The effect is enhanced if the column is charged, as in electrostatic repulsion-hydrophilic interaction chromatography (ERLIC). This combination was exploited in proteomics for the isolation of peptides with certain post-translational modifications (PTMs). The best salt additive examined was magnesium trifluoroacetate. The well-hydrated Mg⁺² ion promoted retention of peptides with functional groups that retained negative charge at low pH, while the poorly hydrated trifluoroacetate counterion tuned down the retention due to the basic residues. The result was an enhancement in selectivity ranging from 6- to 66-fold. These conditions were app

SUBMITTER: Cui Y 

PROVIDER: S-EPMC8237654 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature