Diphosphate—fructose-6-phosphate 1-phosphotransferase also known as PFP is an enzyme of carbohydrate metabolism in plants and some bacteria. The enzyme catalyses the reversible interconversion of fructose 6-phosphate and fructose 1,6-bisphosphate using inorganic pyrophosphate as the phosphoryl donor:diphosphate + D-fructose 6-phosphate $\rightleftharpoons$ phosphate + D-fructose 1,6-bisphosphate
In plants, the PFP is located in the cytosol of the cell and is strongly activated by the signal molecule fructose 2,6-bisphosphate.
Image:Beta-D-fructose-6-phosphate wpmp.png| Fructose 6-phosphate
Image:Beta-D-fructose-1,6-bisphosphate wpmp.png | Fructose 1,6-bisphosphate
PFP is an exclusively cytosolic enzyme that catalyses the phosphorylation of fructose-6-phosphate to fructose-1,6-bisphosphate in the glycolytic direction, and the de-phosphorylation of fructose-1,6-bisphoshate to fructose-6-phosphate in the gluconeogenic reaction. Reeves first isolated PFP from Entamoeba histolytica, a lower eukaryote. The first plant PFP isolated was from the leaves of pineapples by Carnal and Black and it has since been isolated from a variety of plant species and tissues.