| glucose-6-phosphate dehydrogenase deficiency | A deficiency of glucose-6-phosphate dehydrogenase, an enzyme important for maintaining cellular concentrations of reduced nucleotides. Deficiency of this enzyme is the commonest disease-causing enzyme defect in humans affecting an estimated 400 million people. The gene for this enzyme is on the X chromosome and there are various polymorphic forms. Males with the enzyme deficiency develop haemolytic anaemia when red blood cells are exposed to oxidant drugs such as the antimalarial primaquine, the sulfonamide antibiotics or sulfones, naphthalene moth balls, or fava beans. It can also cause anaemia of the newborn, and chronic nonspherocytic haemolytic anaemia. Inheritance: X-linked. (12 Sep 2002) |
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| glucose-6-phosphate isomerase | <enzyme> An enzyme that catalyses the reversible interconversion of glucose-6-phosphate and fructose-6-phosphate, and is a part of the glycolytic and gluconeogenic pathways. Deficiency of the enzyme, an autosomal recessive trait, results in liver glycogenesis and haemolytic anaemia. Chemical name: D-Glucose-6-phosphate ketol-isomerase Registry number: EC 5.3.1.9 (12 Dec 1998) |
| glucose-6-phosphate translocase | <enzyme> A component of EC 3.1.3.9 which transports glucose phosphate into endoplasmic reticulum Registry number: EC 2.7.- Synonym: t1 transport protein (26 Jun 1999) |
| glucose-fructose oxidoreductase | <enzyme> Isolated from zymomonas mobilis; catalyses the formation of sorbitol and glucono-delta-lactone from glucose and fructose; enzyme contains tightly bound nadp+ Registry number: EC 1.1.99.- (26 Jun 1999) |
| glucose-phosphate isomerase | <enzyme> An enzyme that catalyses the reversible interconversion of d-fructose 6-phosphate and d-glucose-6-phosphate; a part of glycolysis and gluconeogenesis; glucosephosphate isomerase deficiency is an inherited disorder resulting in liver glycogenesis and haemolytic anaemia. Synonym: hexosephosphate isomerase, phosphohexomutase, phosphohexose isomerase. (05 Mar 2000) |
| glucosephosphate dehydrogenase | <enzyme> Chemical name: D-Glucose-6-phosphate:NADP+ 1-oxidoreductase Registry number: EC 1.1.1.49 (12 Dec 1998) |
| glucosephosphate dehydrogenase deficiency | A disease-producing enzyme deficiency subject to many variants, some of which cause a deficiency of enzyme activity in erythrocytes, leading to haemolytic anaemia. (12 Dec 1998) |
| glucosephosphate isomerase deficiency | <enzyme> An enzyme deficiency characterised by chronic nonspherocytic haemolytic anaemia; autosomal recessive inheritance. Synonym: phosphohexose isomerase deficiency. (05 Mar 2000) |
| glucosidase | <enzyme> An enzyme catalysing the release of glucose by hydrolysis of the glycosidic link in various B D glucosides, R B D glucose, where the group R may be alkyl, aryl, mono or oligosaccharide. Favoured source: almonds, from which enzyme is known as emulsin. (18 Nov 1997) |
| glucosidase inhibitor | Agents such as acarbose which reduce gastrointestinal absorption of carbohydrates. This group of drugs has been known popularly as "starch blockers". They lower plasma glucose levels and tend to cause weight loss. A limiting side effect is flatulence. (05 Mar 2000) |
| glucosidases | <enzyme> Enzymes that hydrolyze o-glucosyl-compounds. (enzyme nomenclature, 1992) Registry number: EC 3.2.1.- (12 Dec 1998) |
| glucoside | <biochemistry> Any of a number of compounds, typically extracted from plants, that can be hydrolysed into dextrose. (09 Oct 1997) |
| glucosidic linkage | <biochemistry> The linkages between dextrose molecules in a glucoside compound which must be hydrolysed (broken apart) to produce the dextrose molecules. (09 Oct 1997) |
| glucosin | <protein> Any of a group of products resulting from a reaction of ammonia (NH3) with the sugar glucose. Some of these are strong poisons. (09 Oct 1997) |
| glucosinolates | Substituted thioglucosides. They are found in rapeseed (brassica campestris) products and related cruciferae. They are metabolised to a variety of toxic products which are most likely the cause of hepatocytic necrosis in animals and humans. (12 Dec 1998) |