GDP-fucose: beta-N-acetylglucosamine (Fuc to (Fuc alpha 1----6GlcNAc)-Asn-peptide)alpha 1----3-fucosyltransferase activity in honeybee (Apis mellifica) venom glands. The difucosylation of asparagine-bound N-acetylglucosamine |
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| Authors: | E Staudacher F Altmann J Gl?ssl L M?rz H Schachter J P Kamerling K H?rd J F Vliegenthart |
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| Institution: | Institut für Chemie, Universit?t für Bodenkultur, Vienna, Austria. |
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| Abstract: | Incubation of honeybee (Apis mellifica) venom-gland extracts with GDP-14C]fucose and GlcNAc beta 1----2Man alpha 1----6(GlcNAc beta 1----2Man alpha 1----3)Man beta 1----4GlcNAc beta 1----4(Fuc alpha 1----6)GlcNAc beta 1----N-Asn-peptide(NAc) gave a labeled product in 40% yield. Analysis by 500-MHz 1H-NMR spectroscopy indicated the transferred fucose-(Fuc) residue to be alpha 1----3-linked to the Asn-bound GlcNAc. Further proof was provided by one-dimensional and two-dimensional 1H-NMR analysis of the incubation mixture, after incubation with beta-N-acetylhexosaminidase. The established carbohydrate structure (formula; see text) proves the existence of a novel alpha 1----3-fucosyltransferase with the ability to effect difucosylation of the Asn-bound GlcNAc in N-glycans. |
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