Presence of β-linked GalNAc residues on N-glycans of human thyroglobulin
| Autor: | Chizuko Sasaki, Yoshihide Ohe, Hironori Nishijima, Kunio Sugahara, Hiroshi Takeshita, Morihisa Sagi, Osamu Hosomi, Kentaro Yamazaki, Akira Takeya, Tadahisa Kogure, Toshiji Mukai, Hideyuki Hayakawa |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Receptors
N-Acetylglucosamine endocrine system Glycan Acetylgalactosamine endocrine system diseases Swine medicine.medical_treatment Blotting Western Peptide Asialoglycoprotein Receptor Thyroglobulin General Biochemistry Genetics and Molecular Biology N-Acetylgalactosamine chemistry.chemical_compound Polysaccharides parasitic diseases medicine Animals Humans General Pharmacology Toxicology and Pharmaceutics Binding site Receptor chemistry.chemical_classification Binding Sites biology Lectin General Medicine Molecular biology carbohydrates (lipids) Blot chemistry Biochemistry biology.protein Cattle Electrophoresis Polyacrylamide Gel lipids (amino acids peptides and proteins) Plant Lectins Iodine |
| Zdroj: | Life Sciences. 80:538-545 |
| ISSN: | 0024-3205 |
| DOI: | 10.1016/j.lfs.2006.10.004 |
| Popis: | Hepatic asialoglycoprotein receptor, which may mediate the clearance of circulating thyroglobulin, is known to have a high affinity for GalNAc. Recently, the receptor has been reported to be present also in the thyroid, implicating interaction with thyroglobulin. Here, mammalian thyroglobulins were analyzed for GalNAc termini by Western blotting with GalNAc-recognizing lectins labeled with peroxidase or 125 I. Wistaria floribunda lectin was found to bind human thyroglobulin and, to some extent, bovine, but not porcine thyroglobulin. After desialylation, the lectin bound all of the thyroglobulins tested. The binding was inhibited by competitive inhibitor GalNAc. Peptide N -glycanase treatment of human desialylated thyroglobulin resulted in the complete loss of reactivity with W. floribunda lectin, indicating that the binding sites are exclusively on N -glycans. The binding sites on human desialylated thyroglobulin were partly sensitive to β-galactosidase, and the remainder was essentially sensitive to β- N -acetylhexosaminidase. On the other hand, the binding sites of bovine and porcine desialylated thyroglobulins were totally sensitive to β-galactosidase. Thus the lectin binds β-Gal termini, as well as β-GalNAc. GalNAc-specific Dolichos biflorus lectin also bound human thyroglobulin weakly. In contrast to W. floribunda lectin, desialylation diminished binding, suggesting that these two lectins recognize different GalNAc-terminated structures. Again, the binding was inhibited by GalNAc and by treatment with peptide N -glycanase. These results strongly indicate the presence of distinct GalNAc termini of N -glycans on human thyroglobulin. |
| Databáze: | OpenAIRE |
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