Utilizing linkage-specific ethyl-esterification approach to perform in-depth analysis of sialylated N-glycans present on milk whey glycoproteins

Kayili H. M., Barlas N., Demirhan D. B., YAMAN M. E., ATAKAY M., GÜLER Ü., ...More

Food Chemistry, vol.421, 2023 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 421
  • Publication Date: 2023
  • Doi Number: 10.1016/j.foodchem.2023.136166
  • Journal Name: Food Chemistry
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, CAB Abstracts, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, EMBASE, Food Science & Technology Abstracts, MEDLINE, Metadex, Veterinary Science Database, Civil Engineering Abstracts
  • Keywords: Ethyl-esterification, Glycomics, MALDI-MS, Milk, N-glycans, Whey glycoproteins
  • Hacettepe University Affiliated: Yes


Glycosylation of milk whey proteins, specifically the presence of sialic acid-containing glycan residues, causes functional changes in these proteins. This study aimed to analyze the N-glycome of milk whey glycoproteins from various milk sources using a linkage-specific ethyl esterification approach with MALDI-MS (matrix-assisted laser desorption/ionization-mass spectrometry). The results showed that the N-glycan profiles of bovine and buffalo whey mostly overlapped. Acetylated N-glycans were only detected in donkey milk whey at a rate of 16.06%. a2,6-linked N-Acetylneuraminic acid (a2,6-linked NeuAc, E) was found to be the predominant sialylation type in human milk whey (65.16%). The amount of a2,6-linked NeuAc in bovine, buffalo, goat, and donkey whey glycoproteomes was 42.33%, 44.16%, 39.00%, and 34.86%, respectively. The relative abundances of a2,6-linked N-Glycolylneuraminic acid (a2,6-linked NeuGc, Ge) in bovine, buffalo, goat, and donkey whey were 7.52%, 5.41%, 28.24%, and 17.31%, respectively. Goat whey exhibited the highest amount of a2,3-linked N-Glycolylneuraminic acid (a2,3-linked NeuGc, Gl, 8.62%), while bovine and donkey whey contained only 2.14% and 1.11%, respectively.