PFP (enzyme)
Encyclopedia
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:
In plants, the PFP is located in the cytosol
of the cell
and is strongly activated by the signal molecule fructose 2,6-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.
s, specifically those transferring phosphorus-containing groups (phosphotransferase
s) with an alcohol group as acceptor. The systematic name of this enzyme class is diphosphate:D-fructose-6-phosphate 1-phosphotransferase. Other names in common use include:
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
of carbohydrate metabolism
Carbohydrate metabolism
Carbohydrate metabolism denotes the various biochemical processes responsible for the formation, breakdown and interconversion of carbohydrates in living organisms....
in plants and some bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
. The enzyme catalyses the reversible interconversion of fructose 6-phosphate
Fructose 6-phosphate
Fructose 6-phosphate is fructose sugar phosphorylated on carbon 6 . The β-D-form of this compound is very common in cells. The vast majority of glucose and fructose entering a cell will become converted to this at some point...
and fructose 1,6-bisphosphate
Fructose 1,6-bisphosphate
Fructose 1,6-bisphosphate is fructose sugar phosphorylated on carbons 1 and 6 . The β-D-form of this compound is very common in cells...
using inorganic pyrophosphate
Pyrophosphate
In chemistry, the anion, the salts, and the esters of pyrophosphoric acid are called pyrophosphates. Any salt or ester containing two phosphate groups is called a diphosphate. As a food additive, diphosphates are known as E450.- Chemistry :...
as the phosphoryl donor:
- diphosphate + D-fructose 6-phosphate
phosphate + D-fructose 1,6-bisphosphate
In plants, the PFP is located in the cytosol
Cytosol
The cytosol or intracellular fluid is the liquid found inside cells, that is separated into compartments by membranes. For example, the mitochondrial matrix separates the mitochondrion into compartments....
of the cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
and is strongly activated by the signal molecule fructose 2,6-bisphosphate
Fructose 2,6-bisphosphate
Fructose 2,6-bisphosphate abbreviated Fru-2,6-P2, is a metabolite that allosterically affects the activity of the enzymes phosphofructokinase 1 and fructose 1,6-bisphosphatase to regulate glycolysis and gluconeogenesis...
.
PFP is an exclusively cytosolic enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
that catalyses the phosphorylation
Phosphorylation
Phosphorylation is the addition of a phosphate group to a protein or other organic molecule. Phosphorylation activates or deactivates many protein enzymes....
of fructose
Fructose
Fructose, or fruit sugar, is a simple monosaccharide found in many plants. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into the bloodstream during digestion. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847...
-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
Eukaryote
A eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...
. 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.
Nomenclature
This enzyme belongs to the family of transferaseTransferase
In biochemistry, a transferase is an enzyme that catalyzes the transfer of a functional group from one molecule to another . For example, an enzyme that catalyzed this reaction would be a transferase:In this example, A would be the donor, and B would be the acceptor...
s, specifically those transferring phosphorus-containing groups (phosphotransferase
Phosphotransferase
Phosphotransferases are a category of enzymes that catalyze phosphorylation reactions. The general form of the reactions they catalyze is: A—P + B ⇔ B—P + A...
s) with an alcohol group as acceptor. The systematic name of this enzyme class is diphosphate:D-fructose-6-phosphate 1-phosphotransferase. Other names in common use include:
- 6-phosphofructokinase (pyrophosphate),
- inorganic pyrophosphate-dependent phosphofructokinase,
- inorganic pyrophosphate-phosphofructokinase,
- pyrophosphate-dependent phosphofructo-1-kinase, and
- pyrophosphate-fructose 6-phosphate 1-phosphotransferase,
- pyrophosphate-fructose 6-phosphate phosphotransferase