Pyruvate Kinase M2

Pyruvate kinase is the enzyme that catalyzes the final step of glycolysis. It catalyzes the transfer of a phosphate group from phosphoenolpyruvate (PEP) to adenosine diphosphate (ADP), yielding one molecule of pyruvate and one molecule of ATP. Pyruvate kinase is present in four distinct, tissue-specific isozymes, each consisting of particular kinetic properties necessary to accommodate the variations in metabolic requirements of diverse tissues. There are four isozymes of pyruvate kinase in vertebrates: L (liver), R (erythrocytes), M1(muscles, hearts and brain) and M2 (only form detectable in early fetal tissue and present in most adult tissues). R and L isozymes differ from M1 and M2 in that they are both exclusively allosterically and reversibly regulated.