D-Glucosamine 6-phosphate

Haley, F., and H. A. Lardy Phosphoric Esters of Biological Importance. VI. The Synthesis of D-Glucosamine 6-Phosphate and N-Acetyl-D-glucos-amine 6-Phosphate. J. Amer. chem. Soc. 78, 1393 (1956). 

D-glucosamine 6-phosphate to D-glucosamine 1-phosphate. a-D-Glucose 1,6-diphosphate is a cofactor, 264(e)... 

D-Glucosamine is phosphorylated by a hexokinase preparation from yeast. The resulting phosphorylated derivative consumes four moles of periodate per mole and is, therefore, considered to be D-glucosamine 6-phosphate. 

D-Glucosamine 6-phosphate is hydrolyzed by the D-glucose-6-phosphatase of rat-liver mitochondria. The rate of this hydrolysis is about 8 % of that of D-glucose 6-phosphate hydrolysis. A phosphatase which preferentially catalyzes the hydrolysis of D-glucosamine 6-phosphate has been prepared from Neurospora crassa. This enzyme is not stimulated by magnesium ions and has an optimum activity between pH 6 and 7.5. It appears to be distinct from acid, alkaline, and other specific phosphatases. 

D-Glucosamine 6-phosphate can be readily acetylated by a AT-acetylase obtained from a preparation of yeast hexokinase. The resulting iV-acetyl-D-glucosamine 6-phosphate is identified by its Morgan-Elson reaction. The acetyl-coenzyme A which appears to be required for this reaction may be generated by acetate, adenosine-5-triphosphoric acid, and coenzyme A (in the presence of an acetate-activating enzyme). 

AT-Acetyl-D-glucosamine 6-phosphate is metabolized to the D-fructose ester more slowly (by preparations of kidney enzyme) than is D-glucosamine 6-phosphate/ Acetate inhibits the disappearance of AT-acetyl-n-glucos-amine 6-phosphate, but does not affect the disappearance of D-glucosamine 6-phosphate. A possible sequence of reactions for these transformations is as follows. ... 

An extract of Eschericha coli, free from hexoseisomerase, is capable of converting D-glucosamine 6-phosphate to D-fructose 6-phosphate plus ammonia. No added cofactors are required for this reaction. ... 

Acetyl groups of hyaluronate are, most probably, introduced into d-glucosamine 6-phosphate (see Section III, 3). This would be transformed to the W-acetyl-D-glucosamine units, which are then incorporated into the developing hyaluronate molecule. Although acetate exchange may take place with streptococcal hyaluronate, exchange probably does not occur in rabbit hyaluronate. 

Acetyl-CoA + D-glucosamine 6-phosphate = CoA + N-acetyl-D-glucosamine 6-phosphate. 

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