Pyruvate Kinase Assay

Pyruvate kinase (PK) is an enzyme that catalyzes the final step of glycolysis, the transfer of a phosphate group from phospho(enol) pyruvate to ADP, yielding pyruvate and ATP. Pyruvate kinase can regulate gluconeogenesis and additionally, pyruvate kinase deficiency is the second most common cause of hemolytic anemia. This colorimetric assay is based on pyruvate kinase-catalyzed formation of pyruvate, which can be further oxidized, where the formed hydrogen peroxide is catalyzed by peroxidase and reacts with 4-aminoantipyrine to form a colored product. The intensity of the colored reaction product, which exhibits maximum absorbance at 570 nm, is directly proportional to the activity of pyruvate kinase in the sample.