Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.1.1 (hexokinase)
 5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two enzymatic assay procedures for the measurement of 2,5-anhydrohexitol fructose analogs have been devised. Both procedures are based on the measurement of ADP formed during enzymatic phosphorylation of the analogs either by hexokinase or by fructokinase. The actual measurement makes use of the coupled assay system using pyruvate kinase, PEP, lactate dehydrogenase, and NADH. Both systems can be used to measure fructose and appropriate analogs at cuvette concentrations up to 0.10 mM. The hexokinase procedures allows the measurement of fructose, 2,5-anhydromannitol, and 2,5-anhydromannose. Glucose, which also reacts, can be removed by pretreatment of the samples with glucose oxidase. The fructokinase procedure allows the measurement of fructose, 2,5-anhydromannitol, 2,5-anhydroglucitol, and 2,5-anhydrotalitol.
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PMID:Enzymatic analysis of 2,5-anhydro-D-mannitol and related compounds. 641 7

2,5-Anhydro-D-mannitol (100 to 200 mg/kg) decreased blood glucose by 17 to 58% in fasting mice, rats, streptozotocin-diabetic mice, and genetically diabetic db/db mice. Serum lactate in rats was elevated 56% by 2,5-anhydro-D-mannitol, but this could be prevented by dichloroacetate (200 mg/kg) or thiamin (200 mg/kg). In hepatocytes from fasted rats, 1 mM 2,5-anhydro-D-mannitol inhibited gluconeogenesis from a mixture of alanine, lactate, and pyruvate. It also inhibited glucose production and stimulated lactate formation from glycerol or dihydroxyacetone. Glycogenolysis in hepatocytes from fed rats was markedly inhibited by 1 mM 2,5-anhydro-D-mannitol both in the presence or absence of 1 microM glucagon. 2,5-Anhydro-D-mannitol can be phosphorylated by fructokinase or hexokinase to the 1-phosphate and then by phosphofructokinase to the 1,6-bisphosphate. Rat liver glycogen phosphorylase was inhibited by 2,5-anhydro-D-mannitol 1-phosphate (apparent Ki = 0.66 +/- 0.09 mM) but was little affected by 2,5-anhydro-D-mannitol 1,6-bisphosphate. Rat liver phosphoglucomutase was inhibited by 2,5-anhydro-D-mannitol 1-phosphate (apparent Ki = 2.8 +/- 0.2 mM), whereas 2,5-anhydro-D-mannitol 1,6-bisphosphate served as an alternative activator (apparent K alpha = 7.0 +/- 0.5 microM). Rabbit liver pyruvate kinase was activated by 2,5-anhydro-D-mannitol 1,6-bisphosphate (apparent K alpha = 9.5 +/- 0.9 microM), whereas rabbit liver fructose 1,6-bisphosphatase was inhibited by 2,5-anhydro-D-mannitol 1,6-bisphosphate (apparent Ki = 3.6 +/- 0.3 microM). The phosphate esters of 2,5-anhydro-D-mannitol would, therefore, be expected to inhibit glycogenolysis and gluconeogenesis and stimulate glycolysis in liver.
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PMID:Inhibition of gluconeogenesis and glycogenolysis by 2,5-anhydro-D-mannitol. 642 25