Characterization of the Glycans of Equine κ-Casein
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
To study the protein-bound glycans of equine κ-casein, equine sodium caseinate was first obtained from raw mare’s milk by acid precipitation and then fractionated by cation-exchange chromatography. The oligosaccharides of the obtained equine κ-casein were analyzed by RP-HPLC-UV-HRMS after β-elimination with simultaneous derivatization with 1-phenyl-3-methyl-5-pyrazolone (PMP). In addition to the acidic tetrasaccharide derivative Neu5Ac-Gal-[Neu5Ac]-GalNAc-2PMP known from bovine κ-casein, the acidic pentasaccharide derivative Neu5Ac-Gal-[Gal-GlcNAc]-GalNAc-2PMP was identified as the most abundant glycan. The glycosylated amino acid residues were identified using a peptide sequencing approach after digestion with trypsin by HRMS. The threonine T109 was experimentally confirmed for the first time as a glycosylation site in equine κ-casein. Therefore, equine κ-casein seems to be more highly glycosylated than previously thought.
Details
Original language | English |
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Pages (from-to) | 9460-9468 |
Number of pages | 9 |
Journal | Journal of agricultural and food chemistry |
Volume | 71 |
Issue number | 24 |
Publication status | Published - 21 Jun 2023 |
Peer-reviewed | Yes |
External IDs
PubMed | 37282579 |
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Keywords
ASJC Scopus subject areas
Keywords
- equine κ-casein, glycan, mare’s milk, oligosaccharides