Galactose 1-phosphate Gal

Scheme 22 The whole biosynthetic pathway of sugar nucleotides. ATP, adenosine triphosphate Gal-1 -P, galactose-1-phosphate UTP, uridine triphosphate UDP, uridine diphosphate NAD, nicotinamide adenine dinucleotide Fru, fructose AcCoA, acetyl coenzyme-A PEP, phosphoenolpyruvate CTP, cytidine triphosphate NADP, nicotinamide adenine dinucieotide phosphate GTP, guanosine triphosphate.

Galactose 1-phosphate uridyltransferase deficiency (Gal-l-PUT deficiency) is a rare autosomal recessive disorder that results in galac-tosaemia and galactosuria. It is usually manifest shortly after birth when the baby has feeding difficulties, with vomiting and failure to thrive. If not treated, liver damage, mental retardation and formation of cataracts can result. 

Fig. 14. Salvage pathways of nucleotide sugars. L-fucose (11), (3-L-fucose-l-phosphate (12), GDP-p-L-fucose (13), A fucokinase (EC 2.7.1.52), B GDP-Fuc pyrophosphorylase (EC 2.7.7.30). D-galactose (14), a-D-galactose-l-phosphate (15), UDP-a-D-galactose (16), C galactokinase (EC 2.7.1.6), D UDP-Gal pyrophosphorylase. IV-acetyl-D-galactosamine (17), Al-acetyl-a-D-galactosamine-l-phosphate (18), UDP-lV-acetyl-a-D-galactosamine (19), E IV-acetyl-galactosamine kinase (EC 2.7.1. ), F UDP-GalNAc pyrophosphorylase (EC 2.7.7. )...

Figure 2 Examples of glycosyl donors. Nucleotide donors are represented by UDP-galactose (UDP-Gal), GDP-fucose (GDP-Fuc), GMP-N-acetyIneuraminic acid (CMP-sialic acid, CMP-Neu5Ac), GDP-galactose (GDP-Gal), dTDP-rhamnose (dTDP-Rha), and dTDP-daunosamine lipid phosphate donors are represented by Lipid II and dolichol-phosphate-glucose (Dol-P-GIc) sugar phosphate donors are represented by glucose-1-phosphate. The saccharides are transferred from these donors by GTs to form oligo/polysaccharides and glycoconjugate products.

Abbreviations used Gal-l-P, galactose-l-phosphate UDPG, uridine diphosphate glucose G-l-P, glucose-l-phosphate G-6-P, glucose-6-phosphate F-6-P, fructose-6-phosphate F-l,6-P, fructose-1,6-diphosphate G-3-P, glyceraldehyde-3-phosphate DHAP, dihydroxyacetone phosphate F-l-P, fructose-1-phosphate PG, 6-phospho-gluconic acid R-5-P, ribulose-5-phosphate S-7-P, sedoheptulose-7-phosphate. 

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