title: Modelling the electrophoretic migration behaviour of peptides and glycopeptides from glycoprotein digests in capillary electrophoresis-mass spectrometry.
abstract: In this study, the classical semiempirical relationships between the electrophoretic mobility and the charge-to-mass ratio (me vs. q/M(α)) were used to model the migration behaviour of peptides and glycopeptides originated from the digestion of recombinant human erythropoietin (rhEPO), a biologically and therapeutically relevant glycoprotein. The Stoke's law (α=1/3), the classical polymer model (α=1/2) and the Offord's surface law (α=2/3) were evaluated to predict migration of peptides and glycopeptides, with and without sialic acids (SiA), in rhEPO digested with trypsin and trypsin-neuraminidase. The Stoke's law resulted in better correlations for the set of peptides used to evaluate the models, while glycopeptides fitted better with the classical polymer model. Once predicted migration times with both models, it was easy to simulate their separation electropherogram. Results were later validated predicting migration and simulating separation of a different set of rhEPO glycopeptides and also human transferrin (Tf) peptides and glycopeptides. The excellent agreement between the experimental and the simulated electropherograms with rhEPO and Tf digests confirmed the potential applicability of this simple strategy to predict, in general, the peptide-glycopeptide electrophoretic map of any digested glycoprotein.
authors.affiliation: Department of Analytical Chemistry, University of Barcelona, Diagonal 645, 08028 Barcelona, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Barroso
authors.affiliation: Department of Analytical Chemistry, University of Barcelona, Diagonal 645, 08028 Barcelona, Spain.
authors.forename: Estela
authors.initials: E
authors.lastname: Giménez
authors.affiliation: Department of Analytical Chemistry, University of Barcelona, Diagonal 645, 08028 Barcelona, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Benavente
authors.affiliation: Department of Analytical Chemistry, University of Barcelona, Diagonal 645, 08028 Barcelona, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Barbosa
authors.affiliation: Department of Analytical Chemistry, University of Barcelona, Diagonal 645, 08028 Barcelona, Spain. Electronic address: vsanz@ub.edu.
authors.forename: Victoria
authors.initials: V
authors.lastname: Sanz-Nebot
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D006023:Glycoproteins / Q000737:chemistry*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D008962:Models, Theoretical; D010455:Peptides / Q000737:chemistry*
chemical_list: D006023:Glycoproteins; D010455:Peptides
keywords: Capillary electrophoresis; Glycopeptides; Mass spectrometry; Migration prediction; rhEPO