Peanut agglutinin and β-cyclodextrin functionalized polymer monolith: Microextraction of IgG galactosylation coupled with online MS detection

A facile online method coupling polymer monolithic microextraction (PMME) with mass spectrometry (MS) was developed for the detection of Immunoglobulin G (IgG) galactosylation glycopeptides. A peanut agglutinin-beta-cyclodextrin (PNA-beta-CD) functionalized poly(hydroxyethyl methylacrylate-ethyleneglycol dimethacrylate) monolith was designed via a click reaction. Thanking to the specificity of PNA-beta-CD for the targets, the material exhibited enhanced enrichment selectivity and extraction efficiency for IgG galactosylation glycopeptides. Under optimal conditions, the developed method gave a linear range of 0.005-5 pmol for IgG glycopeptides with the regression coefficient greater than 0.9990, and the detection limit of IgG galactosylation glycopeptides as low as 0.5 fmol was achieved. The PMME-MS method was applied to IgG galactosylation glycopeptides in real samples including human serum and acute myelogenous leukemia (AML) cell lysate. A series of unique IgG galactosylation glycopeptides were captured by the monolith in the complex samples, indicating satisfactory enrichment ability for IgG galactosylation glycopeptides. The quick and integrated online PMME-MS method exhibited high selectivity for IgG galactosylation, demonstrating its perspectives on the development and broad applications of MS in studying galactosylation proteins regulated biological processes. (C) 2017 Elsevier B.V. All rights reserved.