The metabolism of aminosugars begins with D-fructose being phosphorylated resulting in the release of Beta-D-fructose 6-phosphate. Beta-D-fructose 6-phosphate can react in 3 different paths: 1.-Beta-D-fructose 6-phosphate reacts with glucosamine 6-phosphate synthase resulting in the release of glucosamine 6-phosphate. This compound then reacts with glucosamine phosphate N-acetyltransferase resulting in the releaase of N-acetyl-D-Glucosamine 6-phosphate. This compound then reacts with a phosphoacetylglucosamine mutase resulting in the release of N-acetyl-glucosamine 1-phosphate. The latter compound reacts with a UTP through a UDP-N-acetylglucosamine pyrophosphorylase resulting in the release of UDP-N-acetylglucosamine. This compound is then used to produce chiting 2.-Beta-D-fructose 6-phosphate reacts with a mannose isomerase to release mannose 6-phosphate. The latter compound then reacts with a phosphomutase resulting in the release of mannose 1-phosphate. This in turn reacts with a GTP through a PSA1 resulting in the release of a guanosine diphosphate mannose. 3.-Beta-D-fructose 6-phosphate reacts with a glucose isomerase to release a beta-d-glucose 6 phosphate. This compound reacts wth phosphoglucomutase resulting in the release of glucose 1phosphate. This compound then reacts with a UTP through a uridinephosphoglucose pyrophosphorylase resulting in the release of UDP and a UDP-glucose. UDP-glucose reacts with a bifunctional protein GAL10 resulting in the release of Uridine diphosphategalactose. This compound reacts in a reversible reaction with glucose 1-phosphate through a Galactose 1-phosphate uridylyltransferase resulting in the release of UDP-glucose and galactose 1-phosphate.

Amino Sugar and Nucleotide Sugar Metabolism References