EC 2.7.1.40

Chemical Properties

White powder

Uses

Pyruvate kinase has been used in the preparation of cell free extract from BL21 CP strain of E. coli culture for highly productive cell-free protein expression. The enzyme has been used to assay the pyruvate kinase activity by incubating with eluted DAPk (Death-associated protein kinase), a serine/threonine kinase that binds and activates pyruvate kinase. It is involved in glycolysis and in gluconeogenesis. It has been used in PGM enzyme assays to determine phosphoglycerate mutase activity. It is also used to study pyruvate kinase (PK) deficiency.

Uses

Pyruvate kinase from Bacillus stearothermophilus has been used in a study to assess evidence that the genes for phosphofructokinase and pyruvate kinase constitute an operon. It has also been used in a study to investigate the importance of the Lys221 active site for pyruvate kinase activity.

Uses

Pyruvate kinase from rabbit muscle has been used in a structural study to understand the reaction mechanism of the final step in glycolysis. It has also been used in a study to investigate ATP-dependent phosphorylation of α-substituted carboxylic acids.

General Description

Pyruvate Kinase (PK) is a glycolysis enzyme and has four isozymes L, R, M₁, and M₂. The L isozyme is localized in gluconeogenic tissues, particularly in the liver. Whereas the R and M₁ are localized in the adult skeletal muscles, heart, brain and erythrocytes, respectively. M₂ is localized in the nucleus of the cells.

Biochem/physiol Actions

Molecular Weight: 237 kDa?and exists as a tetramer of four equal subunits of molecular weight 57 kDa.Isoelectric Point: 7.6Optimal pH: ～7.5 Optimal Temperature: 25°C ΕA280 = 0.54 for 1 mg(p)/ml, 1 cm path Reported KM values are ATP (0.86 mM), pyruvate (10 mM), ADP (0.3 mM), and PEP (0.07 mM) in Tris buffer at pH 7.4 and 30 °C. Pyruvate kinase is highly specific for phosphoenolpyruvate, but can utilize other dinucleotide triphosphates as substrates in place of ATP including GTP, ITP, dATP, UTP, and CTP.

Purification Methods

These are purified by (NH4)2SO4 fractionation and gel filtration, ion-exchange and affinity chromatography. [Garcia-Olalla & Garrido-Pertierra Biochem J 241 573 1987.]