Caenorhabditis elegans N-glycans containing a Gal-Fuc disaccharide unit linked to the innermost GlcNAc residue are recognized by C. elegans galectin LEC-6
| Autor: | Ko Hayama, Tomoharu Takeuchi, Jun Hirabayashi, Ken-ichi Kasai |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Glycan
Binding Sites biology Chemistry Galectins Disaccharide Disaccharides biology.organism_classification Biochemistry carbohydrates (lipids) chemistry.chemical_compound Residue (chemistry) Matrix-assisted laser desorption/ionization Affinity chromatography Polysaccharides Spectrometry Mass Matrix-Assisted Laser Desorption-Ionization biology.protein Animals Binding site Caenorhabditis elegans Caenorhabditis elegans Proteins Galectin |
| Zdroj: | Glycobiology. 18:882-890 |
| ISSN: | 1460-2423 0959-6658 |
| DOI: | 10.1093/glycob/cwn077 |
| Popis: | We report a detailed structural analysis of the N-glycans of Caenorhabditis elegans recognized by C. elegans galectin LEC-6. Glycoproteins of C. elegans captured by an immobilized LEC-6 affinity adsorbent were isolated. The N-glycans of these glycoproteins were then liberated by hydrazinolysis and labeled with the fluorophore 2-aminopyridine (PA). The derived pyridylaminated (PA)-sugars were further fractionated by rechromatography on immobilized LEC-6 adsorbent and by reversed-phase high-performance liquid chromatography (HPLC). The structures of the PA-sugars thus obtained were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS/MS) in conjunction with glycosidase digestion. We confirmed that all PA-sugars having affinity for LEC-6 contain a Gal-Fuc disaccharide unit, and that this unit is bound to the innermost GlcNAc residue of the N-glycan chain. The dissociation constants of LEC-6 for these glycans were measured by frontal affinity chromatography. LEC-6 exhibited higher affinity for oligosaccharides having a Gal-Fuc unit linked to position 6 of the innermost GlcNAc residue than for those having Galbeta1-4GlcNAc units. Affinity for the former disappeared, however, following treatment with beta-galactosidase. If the glycan contained a Hex-Fuc disaccharide linked to the penultimate GlcNAc residue, the affinity would be diminished. We propose, therefore, that the galectins of C. elegans utilize the Gal-Fuc disaccharide unit for recognition instead of the Gal-GlcNAc unit that is common in vertebrates. |
| Databáze: | OpenAIRE |
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