GDP-L-fucose

This enzyme [EC 2.7.7.30] catalyzes the conversion of GTP and L-fucose 1-phosphate to yield GDP-L-fucose and pyrophosphate (or, diphosphate). 

Galactoside 2-L-fucosyltransferase [EC 2.4.1.69], also known as blood group H a-2-fucosyltransferase, catalyzes the reaction of GDP-L-fucose with /8-D-galacto-syl-R to produce GDP and a-L-fucosyl-l,2-/3-D-galac-tosyl-R. Lactose can also act as the acceptor substrate. 

Fucosyltransferase Catalyses the transfer of fucose from GDP L-fucose to specific oligosaccharides and glycoproteins SM... 

A similar mechanism seems probable for conversion of GDP-6-deoxy-D-(yxo-hexos-4-ulose (7c) into GDP-L-fucose (GDP-Fuc),40,159 although, in this case, the enzymes that participated in the process were not separated, and intermediate formation of the 6-deoxy-L-xy/o-hexosyl-4-ulose derivative (8b) was not demonstrated. 

Larsen, R. D., L. K. Ernest, R. P. Nair, and J. B. Lowe, Molecular cloning sequence and expression of a human GDP-L-fucose /3-n-galactosidase 2-a-L-fucosyltransferase cDNA that can form the H blood group antigen. Proc. Natl. Acad. Sci. USA 87 6674-6678, 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...

Jarvinen N, Maki M, Rabina J et al (2001) Cloning and expression of Helicobacter pylori GDP-l-fucose synthesizing enzymes (GMD and GMER) in Saccharomyces cerevisiae. Eur J Biochem 268 6458-6464... 

By analogy to results obtained in studies on the biosynthesis of dTDP-L-rhamnose,18 dTDP-6-deoxy-L-talose,17 and GDP-L-fucose,41 it seems very likely that dTDP-6-deoxy-L-/yxo-hexos-4-ulose (21), formed by the 3,5-epimerase reaction, remains enzyme-bound. 

UDP-D-xylose, GDP-D-mannose, GDP-L-Fucose, or CMP-D-A-acetylneuraminic acid. Mammalian GTs also use dolichol-diphosphate-GlcNAc2Man9GlC3, dolichol-phosphate-mannose and dolichol-phosphate-glucose (Fig. 2). 

Ernst, L. K., Rajan, V. P., Larsen, R. D., Ruff, M. M. and Lowe, J. B. (1989). Stable expression of blood group H determinants and GDP-L-fucose 0-D-galactoside 2-a-L-fucosyltransferase in mouse cells after transfection with human DNA. J. Biol. Chem. 264, 3436-3447. 

Luengo, J I, Gleason, J G, Synthesis of C-fucopyranosyl analogs of GDP-L-fucose as inhihitors of fucosyltransferases. Tetrahedron Lett., 33, 6911-6914, 1992. 

Human a-l,3-fucosyltransferases are found in milk,51 53 saliva,54 and other specific cell lines.55-57 Through cloning studies, a role for an a-1,3-fucosyltransferase in cell adhesion was identified for the biosynthesis of sialyl Lewisxon neutrophils.58-59 As these studies link a-l,3-fucosyltransferase to cell adhesion and since the activated fucose species used by this enzyme is GDP-L-fucose, Luengo, et al.,eo prepared the C-glycoside analog of GDP-fucose shown in Figure 1.4.4. 

A separate enzyme, a 3,5-epimerase catalyzes inversion at both C-3 and C-5 (step Einally, a third enzyme is needed for a second reduction (step e) using NADPH. f The bios5mthesis of GDP-L-fucose from GDP-D-mannose occurs by a parallel sequence. ... 

Further progress has been made in the more complex conversions, involving the change in configuration at several carbon atoms, that occur in the process of formation of 6-deoxyhexoses, namely, the conversion of GDP-D-mannose into GDP-L-fucose, and dTDP-D-glucose into dTDP-L-rhamnose. 

D-mannose, to GDP-L-fucose. They examined three types of bacteria, the first synthesizing polysaccharides containing D-mannose but not L-fucose, the second synthesizing those containing L-fucose but not D-mannose, and the third synthesizing those containing both. Their findings are summarized in the next Scheme, where broken lines indicate the action of feed-back inhibitors. 

Thus, in the first group of bacteria, GDP-D-mannose inhibits its own synthesis by a simple feed-back inhibition. A similar mechanism is also operative in the second group, where GDP-L-fucose inhibits both GDP-D-mannose pyrophosphorylase and GDP-D-mannose oxi-doreductase. In the third group, where both sugar nucleotides are needed for polysaccharide synthesis, their biosynthesis is individually controlled, so that imbalance in the supply of these two sugars will not occur. 

Wu B-Y, Zhang Y-X, Wang PG. Identification and characterization of GDP-D-mannose 4,6-dehydratase and GDP-L-fucose synthetase in a GDP-L-fucose biosynthetic gene cluster from Helicobacter pylori. Biochem Biophys Res Commun 2001 285 364-371. 

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