Oligosaccharide specificity of normal human hepatocyte alpha 1-3 fucosyltransferase
| Autor: | Maryvonne Jezequel-Cuer, Geneviève Durand, Daniel Biou, Han N'Guyen-Cong |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Glycosylation
Fucosyltransferase Molecular Sequence Data Biophysics Alpha (ethology) Golgi Apparatus Neuraminidase Oligosaccharides Cell Fractionation Biochemistry Fucose Substrate Specificity Fucosyltransferases chemistry.chemical_compound medicine Humans Molecular Biology chemistry.chemical_classification biology Oligosaccharide Kinetics medicine.anatomical_structure chemistry Carbohydrate Sequence Liver Hepatocyte Galactose biology.protein |
| Zdroj: | Biochimica et biophysica acta. 1157(3) |
| ISSN: | 0006-3002 |
| Popis: | A purified alpha 1-3 fucosyltransferase (alpha 1-3 FT) was recovered in the Golgi fraction of isolated hepatocytes from normal human liver tissue. The efficiency of purification was controlled by measurement of fucose transfer to asialotransferrin (for alpha 1-3 FT), to phenyl-beta-D-galactose (for alpha 1-2 FT) and to 2' fucosyl lactose (for alpha 1-3/4 FT). The initial hepatocyte isolation step got rid of 97% and 94% of alpha 1-2 and alpha 1-3/4 total liver FT, respectively. After Golgi enrichment (26-fold purification and a yield of 7.6%), alpha 1-3 FT extract expressed a specific activity of 2 pM/min per mg protein. When incubated in optimized conditions with type 1, 2 or 6 oligosaccharide acceptors (10 mM), hepatocellular alpha 1-3 FT efficiently transferred fucose to N-acetyllactosamine and its 3' sialylated derivative, but poorly to lactose. When incubated with neutral or sialylated biantennary N-glycans, the enzyme expressed the highest affinity (Km = 0.38 mM) for the 3'bisialylated derivative. This suggests that hepatocellular alpha 1-3 FT is involved in the synthesis of sialosyl Le(x) determinants on cirrhotic alpha 1AGP. |
| Databáze: | OpenAIRE |
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