Fractionation and characterization of sialyl linkage isomers of serum N-glycans by CE-MS.
J Sep Sci
; 45(17): 3348-3361, 2022 Sep.
Article
en En
| MEDLINE
| ID: mdl-35819141
ABSTRACT
Structural isomers of sialylated N-glycans contribute to the diversity of the N-glycome and to a range of biological functions. Sialyl linkage isomers can be readily distinguished by mass spectrometry with mass differences between α2,3- and α2,6-linkages generated by a two-step sialic acid linkage-specific alkylamidation. To improve the identification of N-glycans from complex mixtures, we added a delactonization step after the first alkylamidation step, which regenerates negatively charged carboxylic acids on α2,3-sialic acids. N-glycan isomers with α2,3-sialic acids are then fractionated by ion-exchange chromatography prior to the second alkylamidation step. With this modified alkylamidation method, sialylated N-glycans were enriched and stabilized for structural characterization by capillary electrophoresis-mass spectrometry and tandem mass spectrometry. We identified 52 sialylated N-glycan structures, including 107 linkage isomers, in human serum and confirmed the presence of positional isomers of specific sialyl linkage isomers. Due to the reduced sample complexity after ion-exchange fractionation and CE separation, substructural features of N-glycans were rapidly evaluated and included core- and antenna-fucosylation and poly-lactosamine.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Polisacáridos
/
Espectrometría de Masas en Tándem
Límite:
Humans
Idioma:
En
Revista:
J Sep Sci
Año:
2022
Tipo del documento:
Article
País de afiliación:
Estados Unidos