Synonym: ATP:pyruvate 2-O-phosphotransferase, PK
CAS Number: 9001-59-6
Enzyme Commission (EC) Number: 2.7.1.40
MDL Number: MFCD00081946
Analysis Note
Protein determined by biuret.
General Description
Pyruvate kinase from rabbit muscle catalyzes an ATP-dependent phosphorylation of glycolate to yield 2-phosphoglycolate.
Unit Definition
One unit will convert 1.0 μmole of phospho(enol)pyruvate to pyruvate per min at pH 7.6 at 37 °C.
Physical Form
Suspension in 3.2 M (NH4)2SO4 solution, pH 6
Application
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.
Biochem/physiol Actions
Molecular Weight: 237 kDa and exists as a tetramer of four equal subunits of molecular weight 57 kDa.
Isoelectric Point: 7.6
Optimal 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.
Pyruvate kinase from rabbit muscle can be activated by histidine and inhibited by low levels of zinc (Zn2+).
Type: Type II
Form: ammonium sulfate suspension
Foreign Activity: lactic dehydrogenase, creatine phosphokinase, and myokinase ≤0.01%; phosphoglucomutase ≤0.05%
Storage Temp.: 2-8°C