Phosphofructokinase 2

PFKFB is Phosphofructokinase-2/Fructose-2 ,6- bisphosphatase, the name for proteins that have a double function of the enzyme, and of which there are four isoforms in humans, with the corresponding genes PFKFB1, PFKFB2, PFKFB3 and PFKFB4. Depending on whether the protein has been phosphorylated, to catalyze a reaction step in glycolysis ( EC 2.7.1.105 ) and gluconeogenesis ( EC 3.1.3.46 ). It is a molecular switch. PFKFB1 is mainly formed in the liver and in the heart PFKFB2, wherein there is at the phosphorylation of the bifunctional enzyme to increased kinase activity. This increased glycolysis in adrenaline and related increased PKA activity still possible. Although PFKFB3 has no preferential localization, but may produce amplified in tumors. PFKFB4 was found in the testes.

Catalyzed reactions

ATP ADP ⇔

The enzyme function is to catalyze the phosphorylation of fructose -6-phosphate to fructose -2 ,6- bisphosphate, an important regulator of glycolysis and gluconeogenesis. This reaction results from the dephosphorylated form of the enzyme ( phosphofructokinase -2). It must not be confused with ,6- bisphosphate formation of fructose - 1 by the phosphofructokinase 1, a central step of glycolysis.

H2O ⇔ phosphate

The other function is to catalyze the cleavage of a phosphate ion of fructose -2 ,6- bisphosphate. This is accomplished by the phosphorylated form of the enzyme ( fructose -2 ,6- bisphosphatase ).

Are the two non- catalysed reactions for mutual reversal reactions, since it is consumed in the first ATP, the second with free- formed phosphate. Also, the two catalytic centers at different positions in the molecule.