Fucosyl transferases

This class of enzymes includes galactoside 3(4)-L-fucosyl-transferase, [EC 2.4.1.65] glycoprotein 6-a-L-fucosyl-transferase [EC 2.4.1.68], galactoside 2-ce-L-fucosyltran-sferase [EC 2.4.1.69], and galactoside 3-fucosyltransferase [EC 2.4.1.152]. 

J. B. Lowe, L. M. Stoolman, R. P. Nair, R. D. Larsen, T. L. Berhend, and R.M. Marks, ELAM-1-dependent cell adhesion to vascular endothelium determinant by a transfected human fucosyl-transferase cDNA, Cell 63 475 (1990). 

Fig. 25.—Sequence of Reactions Catalyzed by UDP-2-acetamido-2-deoxy-D-glucose a-D-mannoside-2-acetamido-2-deoxy-D-gluco-syltransferases I and II of Chinese-hamster, Ovary Cells154-1" and by GDP-L-fucose 2-acetamido-2-deoxy-/3-D-glucoside-L-fucosyl-transferase from Rat Liver.158-157...

M. M. A. Olsthoorn, I. M. Lopez-Lara, B. O. Petersen, K. Bock, J. Haverkamp, H. P. Spaink, and J. E. Thomas-Oates, Novel branched nod factor structure results from a-(l->3) fucosyl transferase activity The major lipo-chitin oligosaccharides from Mesorhizobium loti strain NZP2213 bear an a-(l->3) fucosyl substituent on a nonterminal backbone residue, Biochemistry, 37 (1998) 9024-9032. 

Fig. 3. Representative pathway for the biosynthesis of Asn-linked oligosaccharide. Biosynthesis starts in the rough endoplasmic reticulum and proceeds through the cis-, medial-, and trans-Golgi apparatus, before glycoprotein is secreted. Some of the enzymes involved are oligosaccharyl transferase (OST) a-glucosidase I II (aG I II) ER-mannosidase (aM) a-mannosidase I II (aM I II) N-acetylglucosaminyl transferase I II (GnT I II) fucosyl transferase (FucT) galactosyl transferase (GalT) sialyl transferase (ST). n-Gn O-Man -Glc V-Fuc A-Gal O-SA (adopted from [40])...

Fucosyl transferases use GDP Fuc 10.59, which may be prepared on a gram scale from L-fucose (Adelhorst and Whitesides 1993 Veeneman etal. 1991). Hermann et al. (1993) proposed fucosylation with regeneration in a similar manner to one of the biosynthetic routes of fucose according to the reactions (10.15), whose similarity to reactions (10.9) to (10.12) will not escape the reader. The a-D-mannopyranosyl phosphate can be prepared rapidly by a non-enzymic route. 

This is the most complex form of cytoplasmic glycosylation yet reported. Since both the native acceptor protein and the fucosyl transferase are novel, studying this pair in Dictyostelium should provide functional insights and the necessary tools to probe for counterparts in higher organisms. 

Fig. 10. Transfer of sneaky-B (a GDP-derivative of fucose carrying B-trisaccharide ) by fucosyl transferase.

Fig. 9 Knockout of xylosyl transferase in moss. To avoid undesired glycosylation, greenovation knocked out the xylosyl and fucosyl transferase, as confirmed by RT-PCR. MALDI-TOF results (Professor F. Altmann, Vienna) show that, indeed, xylosyl and fucosyl residues were completely removed from the glycosylation pattern of the expressed protein (data for knockout of fucosyl transferase not shown) [24].

Bryan MC, Lee LV, Wong CH. High-throughput identification of fucosyl-transferase inhibitors using carbohydrate microarrays. Bioorg Med Chem Lett 2004 14 3185-3188. 

Scheme 10.10 Cu-mediated synthesis and direct screening of fucosyl transferase inhibitors.

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