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 ?
Antonacci et al., "Phosphoglucomutase genetic polymorphism and body mass," American Journal of the Medical Sciences, vol.
Choi, "Cloning and characterization of phosphoglucomutase and phosphomannomutase derived from Sphingomonas chungbukensis DJ77," Journal of Biochemistry, vol.
Nuclear gene differences were also evident in phosphoglucomutase intron sequences, but Pgm-i haplotypes were not reciprocally monophyletic and interspecific divergence was not as deep as with COI.
The buffers and the 20 enzyme systems analyzed were; 1) Clayton & Tretiak (1972) buffer: Aspartate amino transferase (AAT; 2.6.1.1), Aconitate hydratase (ACO; 4.2.1.3), Malic enzyme (ME; 1.1.1.40), Glycerol-3phosphate dehydrogenase (G3PDH; 1.1.1.8), Isocitrate dehydrogenase (IDH; 1.1.1.42), Malate dehydrogenase (MDH; 1.1.1.37), Glucose-6-phosphate dehydrogenase (6PGD; 1.1.1.49), Phosphoglucomutase (PGM; 5.4.
HCI buffer (H) pH, 7.0, Continuous tried Tris Citrate-I (CTC-I) pH 8.0, Continuous Tris Citrate-II (CTC-II) pH 7.0, Tris-Borate-EDTA (TBE) pH 8.5 4 Enzymes tried Esterase (EST), Glucose-6-phosphate dehydrogenase (G6PDH), Malate dehydrogenase (MDH), Malic enzyme (ME), 6-phosphogluconate dehydrogenase (6PGDH), phosphoglucoisomerase (PGI), phosphoglucomutase (PGM), menadione reductase (MR), shikimic acid dehydrogenase (SKDH).
Eight enzymes (9 loci) were tested for polymorphism: fumarate hydratase (FUM), aspartate minotransferase (GOT1, GOT2), isocitrate dehydrogenase (IDH),lactate dehydrogenase (LDH), mannose phosphate isomerase (MPI), phosphoglucose isomerase (PGI), phosphoglucomutase (PGM), and 6-phosphogluconate dehydrogenase (6PGDH).
Malate dehydrogenase (MDH) and phosphoglucose isomerase (PGI) were resolved with a histidine-citrate pH 5.7, and glutamate oxaloacetate transaminase (GOT) and phosphoglucomutase (PGM) were resolved with a lithium-borate pH 8.3 buffer systems (Stuber et al., 1988).
Enzymes of normal and malignant trophoblast: phosphoglucose isomerase, phosphoglucomutase, hexokinase, lactate dehydrogenase, and alkaline phosphatase.
Phosphoglucomutase polymorphism in Pacific ocean perch, Sebastes alutus.
Five loci (Acon, aconitase; Idh, isocitric dehydrogenase; 6Pgd, 6-phosphogluconate dehydrogenase; Pgm, phosphoglucomutase; and Gpi, glucosephosphate isomerase) were polymorphic.
Crosses allowing pollen competition between individuals of known genotype at the phosphoglucomutase locus revealed that control fathers sired 15% more seeds than defoliated fathers.
contorta 4 2 (*) * This locus was not polymorphic for the species We examined the genotype of each sampled trunk using horizontal starch gel protein electrophoresis, assaying for the following allozymes: acid phosphatase (ACP), alcohol dehydrogenase (ADH), fluorescent esterase (FE), glutamate dehydrogenase (GDH), glutamate oxaloacetate (GOT), isocitrate dehydrogenase (IDH), leucine aminopeptidase (LAP), malate dehydrogenase (MDH), peroxidase (PER), 6-phosphogluconate dehydrogenase (6-PGD), phosphoglucose isomerase (PGI), and phosphoglucomutase (PGM).

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