title: Ligand and pathogen specificity of the Atlantic salmon serum C-type lectin.
abstract: BACKGROUND
  An Atlantic salmon (Salmo salar) C-type lectin (SSL) binds to mannose and related sugars as well as to the surface of Aeromonas salmonicida. To characterize this lectin as a pathogen recognition receptor in salmon, aspects of its interaction with molecules and with intact pathogens were investigated.
  
  
  METHODS
  SSL was isolated using whole-yeast-affinity and mannan-affinity chromatography. The binding of SSL to the two major surface molecules of A. salmonicida, lipopolysaccharide (LPS) and A-layer protein was investigated by western blotting and enzyme-linked immunosorbent assays. Microbial binding specificity of SSL was examined by whole cell binding assays using a range of species. Carbohydrate ligand specificity of SSL was examined using glycan array analysis and frontal affinity chromatography.
  
  
  RESULTS
  SSL showed binding to bacteria and yeast including, Pseudomonas fluorescens, A. salmonicida, A. hydrophila, Pichia pastoris, and Saccharomyces cerevisiae, but there was no detectable binding to Yersinia ruckeri. In antimicrobial assays, SSL showed no activity against Escherichia coli, Bacillus subtilis, S. cerevisiae, or A. salmonicida, but it was found to agglutinate E. coli. The major surface molecule of A. salmonicida recognized by SSL was shown to be LPS and not the A-layer protein. LPS binding was mannose-inhibitable. Glycans containing N-acetylglucosamine were shown to be predominant ligands.
  
  
  CONCLUSIONS
  SSL has a distinct ligand preference while allowing recognition of a wide variety of related carbohydrate structures.
  
  
  CONCLUSIONS
  SSL is likely to function as a wide-spectrum pattern recognition protein.
authors.affiliation: Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada.
authors.forename: Elke
authors.initials: E
authors.lastname: Uribe
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Steele
authors.forename: Robert C
authors.initials: RC
authors.lastname: Richards
authors.forename: K Vanya
authors.initials: KV
authors.lastname: Ewart
mesh_terms: D000818:Animals; D001419:Bacteria / Q000737:chemistry* / Q000378:metabolism; D029941:Fish Proteins / Q000737:chemistry* / Q000378:metabolism; D005667:Furunculosis / Q000378:metabolism; D037181:Lectins, C-Type / Q000737:chemistry* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000378:metabolism; D010843:Pichia / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000378:metabolism; D020317:Salmo salar
chemical_list: D029941:Fish Proteins; D037181:Lectins, C-Type; D008070:Lipopolysaccharides