ⓘ Phosphofructokinase 2

                                     

ⓘ Phosphofructokinase 2

Phosphofructokinase-2 or fructose bisphosphatase-2, is an enzyme indirectly responsible for regulating the rates of glycolysis and gluconeogenesis in cells. It catalyzes formation and degradation of a significant allosteric regulator, fructose-2.6-bisphosphate from substrate fructose-6-phosphate. Fru-2.6-P 2 contributes to the rate-determining step of glycolysis as it activates enzyme phosphofructokinase 1 in the glycolysis pathway, and inhibits fructose-1.6-bisphosphatase 1 in gluconeogenesis. Since Fru-2.6-P 2 differentially regulates glycolysis and gluconeogenesis, it can act as a key signal to switch between the opposing pathways. Because PFK-2 produces Fru-2.6-P 2 in response to hormonal signaling, metabolism can be more sensitively and efficiently controlled to align with the organisms glycolytic needs.

PFK-2 is known as the "bifunctional enzyme" because of its distinctive structure: although both are on the same homodimer of the protein, its two domains to act as independently functioning enzymes. One Terminus is the domain for kinase PFK-2, and the second end acts as the domain phosphatase FBPase-2.

In mammals, genetic coding mechanisms of different PFK-2 isoforms to meet the needs of a particular tissue. While the overall function remains the same, the isoforms have subtle differences in enzymatic properties, and are under the control of different control methods, these differences will be discussed below.