Phosphoglucomutase


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phosphoglucomutase

[¦fäs·fō¦glü·kō′myü‚tās]
(biochemistry)
An enzyme that catalyzes the conversion of glucose-1-phosphate to glucose-6-phosphate.

Phosphoglucomutase

 

an enzyme of the transferase class that plays an important part in carbohydrate metabolism. Phosphoglucomutase catalyzes what is outwardly an intramolecular transfer of phosphate during the formation of glucose-6-phosphate from glucose-1-phosphate during glycolysis. The transfer, which occurs in the reaction following the phosphorolysis of glycogen, is as follows:

Phosphate is transferred from carbon atom 1 in one glucose molecule to carbon atom 6 in another molecule; glucose-1,6-diphos-phate acts as a coenzyme of the reaction, which requires the presence of Mg2+ ions. In the reaction, the phosphorylated form of phosphoglucomutase transfers the phosphate to carbon atom 6 of glucose-1-phosphate, forming glucose-1,6-diphosphate. The de-phosphorylated phosphoglucomutase then takes on the phosphate group at carbon atom 1 of glucose-1,6-diphosphate. Thus, glucose-6-phosphate is formed, and the enzyme again assumes its phosphorylated form. Glucose-1,6-diphosphate may also be formed by means of the kinase-catalyzed reaction

glucose-1-phosphate + adenosine triphosphate
→ glucose-1, 6-diphosphate + adenosine diphosphate

Phosphoglucomutase is widely distributed in plant, animal, and microbe cells; within the cell, it is located in the cytoplasm. The enzyme is obtained from various sources in a highly purified form; a protein, it has a molecular weight of 60,000–112,000. Phosphoglucomutase may be present in an organism in a number of different forms. Known as isoenzymes, these forms are similar with regard to protein activity. Characteristic sets of isoenzymes of phosphoglucomutase have been discovered in the erythrocytes, liver, kidneys, muscles, and placenta of humans. Phosphoglucomutase contains a residue of serine that is necessary for catalytic activity.

V. V. ZUEVSKII

References in periodicals archive ?
Genetically-determined polymorphism of nonspecific esterases and phosphoglucomutase in eight introduced breeds of the silkworm, Bombyx mori, raised in Bulgaria.
In the Beutler enzyme spot test, GALT enzyme activity is monitored with the aid of phosphoglucomutase and glucose-6-phosphate dehydrogenase (G6PD) and visualization of the fluorescence of reduced [NADP.
Phosphoglucomutase (Pgm), glutamate oxaloacetate transaminase (Got) (= aspartate aminotransferase), menadione reductase (Mnr) (= diaphorase), malic enzyme (Me), and peroxidase (Per) were stained according to procedures described in Soltis et al.
Electrophoretic analysis was successfully performed for nine enzyme systems: isocitrate dehydrogenase, malate dehydrogenase, malic enzyme, acid phosphatase, hexokinase, mannose-phosphate-isomerase, phosphohexose isomerase, phosphoglucomutase, and [Alpha]-glycerophosphate dehydrogenase, (Table 4).
The genetic markers were electrophoretic variants of phosphoglucomutase (PGM, Enzyme Code Number 2.
Both M1-2 and M6-1 (PI 613165) (Yu, 2001) are resistant to root-knot nematode, but their reactions to phosphoglucomutase (PGM) isozyme stain on starch gels are different.
57760), phosphoglucomutase (from chicken muscle; [alpha]-D-glucose 1,6-phosphomutase; EC 5.
The enzymes phosphogulcose isomerase (Pgi), phosphoglucomutase (Pgm), ribulose 5[prime]diphosphate carboxylase (Rub) were assayed with the Histidine system and acid phosphatase (Acph), anodic peroxidase (Apx), and esterase (Est) were resolved with the Poulik system.
The enzymes and their EC (Enzyme Commission) codes were: phosphoglucomutase (PGM, EC 5.
The enzymes assayed were acid phosphatase (Acp), aspartate aminotransferase (Aat), [Beta]-esterase ([Beta]-Est), NADP-dependent isocitrate dehydrogenase (Idh), glyceraldehyde-3-phosphate dehydrogenase (G3pd), phosphoglucoisomerase (Pgi), and phosphoglucomutase (Pgm).
We were able to score unambiguously nine polymorphic loci (lactate dehydrogenase, LDH-A; malate dehydrogenase, MDH-1,2; aspartate aminotransferase, sAAT; leu-ala substrate, LA-2; mannose-6-phosphate isomerase, MPI; glucose-6-phospate isomerase, GPI; phosphoglucomutase, PGM-1,2).
An isozyme pattern of phosphoglucomutase (PGM) has been shown to be associated with root-knot nematode resistance found in the Mi-1 Beta germplasm lines.

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