On-line selective enrichment and ion-pair reaction for structural determination of sulfated glycopeptides by capillary electrophoresis-mass spectrometry.
We describe a new capillary electrophoresis-mass spectrometry (CE-MS)-based technique for analyzing sulfated glycopeptides. The proposed method performs selective enrichment of sulfated glycopeptides from a complex mixture of peptides based on field-enhanced sample injection and ion-pair reaction with a basic ion-pair reagent (Lys-Lys-Lys; KKK) at the exit end of a capillary in a single analysis, which permits successful fragmentation of sulfated glycopeptides in positive-ion mode at the MS/MS stage for comprehensive structural analysis. In this study, the method was verified using a model sulfated monosaccharide, N-acetyl-d-galactosamine 4-sulfate (GalNAc 4S). As an example of an application of this method, sulfated glycopeptides were selectively enriched from the enzymatic digest of thyroid stimulating hormone, affording approximately 500-fold sensitivity enhancement, and structural information was successfully obtained via on-line ion-pair complexation reaction.
Imami
Koshi
K
Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo 678-1297, Japan. imami@sfc.keio.ac.jp
Ishihama
Yasushi
Y
Terabe
Shigeru
S
D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D006020:Glycopeptides / Q000032:analysis* / Q000737:chemistry; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D015394:Molecular Structure; D015203:Reproducibility of Results; D013463:Sulfuric Acid Esters / Q000032:analysis* / Q000737:chemistry
D006020:Glycopeptides; D013463:Sulfuric Acid Esters