Atlantic Salmon Carries a Range of Novel O-Glycan Structures Differentially Localized on Skin and Intestinal Mucins

J Proteome Res. 2015 Aug 7;14(8):3239-51. doi: 10.1021/acs.jproteome.5b00232. Epub 2015 Jun 26.


Aquaculture is a growing industry, increasing the need for understanding host-pathogen interactions in fish. The skin and mucosal surfaces, covered by a mucus layer composed of mucins, is the first point of contact between fish and pathogens. Highly O-glycosylated mucins have been shown to be an important part of the defense against pathogens, and pathogens bind to host surfaces using lectin-like adhesins. However, knowledge of piscine O-glycosylation is very limited. We characterized mucin O-glycosylation of five freshwater acclimated Atlantic salmon, using mass spectrometry. Of the 109 O-glycans found, most were sialylated and differed in distribution among skin, pyloric ceca, and proximal and distal intestine. Skin O-glycans were shorter (2-6 residues) and less diverse (33 structures) than intestinal O-glycans (2-13 residues, 93 structures). Skin mucins carried O-glycan cores 1, 2, 3, and 5 and three types of sialic acids (Neu5Ac, Neu5Gc, and Kdn) and had sialyl-Tn as the predominant structure. Intestinal mucins carried only cores 1, 2, and 5, Neu5Ac was the only sialic acid present, and sialylated core 5 was the most dominant structure. This structural characterization can be used for identifying structures of putative importance in host-pathogen interactions for further testing in biological assays and disease intervention therapies.

Keywords: Atlantic salmon; O-glycan; fish; gastrointestinal tract; glycosylation; mucins; mucus; skin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carbohydrate Sequence
  • Chromatography, Liquid
  • Fish Proteins / metabolism*
  • Fucose / chemistry
  • Fucose / metabolism
  • Gastrointestinal Tract / metabolism*
  • Glycomics / methods
  • Glycosylation
  • Molecular Sequence Data
  • Mucins / chemistry
  • Mucins / metabolism*
  • Neuraminidase / metabolism
  • Organ Specificity
  • Polysaccharides / chemistry
  • Polysaccharides / metabolism*
  • Salmo salar / metabolism*
  • Sialic Acids / chemistry
  • Sialic Acids / metabolism
  • Skin / metabolism*
  • Tandem Mass Spectrometry


  • Fish Proteins
  • Mucins
  • Polysaccharides
  • Sialic Acids
  • Fucose
  • Neuraminidase