Fructose 1,6-bisphosphate, also known as Harden-Young ester, is

fructose Fructose, or fruit sugar, is a ketonic simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbe ...

sugar

phosphorylated In chemistry, phosphorylation is the attachment of a phosphate group to a molecule or an ion. This process and its inverse, dephosphorylation, are common in biology and could be driven by natural selection. Text was copied from this source, whi ...

on carbons 1 and 6 (i.e., is a fructosephosphate). The β-D-form of this compound is common in

cells Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...

. Upon entering the cell, most

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using ...

and fructose is converted to fructose 1,6-bisphosphate.

In glycolysis

Fructose 1,6-bisphosphate lies within the

glycolysis Glycolysis is the metabolic pathway that converts glucose () into pyruvate (). The free energy released in this process is used to form the high-energy molecules adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide (NADH) ...

metabolic pathway In biochemistry, a metabolic pathway is a linked series of chemical reactions occurring within a cell. The reactants, products, and intermediates of an enzymatic reaction are known as metabolites, which are modified by a sequence of chemical rea ...

and is produced by phosphorylation of

fructose 6-phosphate Fructose 6-phosphate (sometimes called the Neuberg ester) is a derivative of fructose, which has been phosphorylated at the 6-hydroxy group. It is one of several possible fructosephosphates. The β-D-form of this compound is very common in cells. ...

. It is, in turn, broken down into two compounds:

glyceraldehyde 3-phosphate Glyceraldehyde 3-phosphate, also known as triose phosphate or 3-phosphoglyceraldehyde and abbreviated as G3P, GA3P, GADP, GAP, TP, GALP or PGAL, is a metabolite that occurs as an intermediate in several central pathways of all organisms.Nelson, D ...

and

dihydroxyacetone phosphate Dihydroxyacetone phosphate (DHAP, also glycerone phosphate in older texts) is the anion with the formula HOCH2C(O)CH2OPO32-. This anion is involved in many metabolic pathways, including the Calvin cycle in plants and glycolysis.Nelson, D. L.; Co ...

. It is an

allosteric In biochemistry, allosteric regulation (or allosteric control) is the regulation of an enzyme by binding an effector molecule at a site other than the enzyme's active site. The site to which the effector binds is termed the ''allosteric site ...

activator of

pyruvate kinase Pyruvate kinase is the enzyme involved in the last 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. Pyru ...

through distinct interactions of binding and allostery at the enzyme's catalytic site

''The numbering of the carbon atoms indicates the fate of the carbons according to their position in fructose 6-phosphate.''

Isomerism

Fructose 1,6-bisphosphate has only one biologically active

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. I ...

, the β-D-form. There are many other isomers, analogous to those of fructose.

Iron chelation

Fructose 1,6-bis(phosphate) has also been implicated in the ability to bind and sequester Fe(II), a soluble form of iron whose oxidation to the insoluble Fe(III) is capable of generating reactive oxygen species via Fenton chemistry. The ability of fructose 1,6-bis(phosphate) to bind Fe(II) may prevent such electron transfers, and thus act as an antioxidant within the body. Certain neurodegenerative diseases, like

Alzheimer's Alzheimer's disease (AD) is a neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As t ...

and

Parkinson's Parkinson's disease (PD), or simply Parkinson's, is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms becom ...

, have been linked to metal deposits with high iron content, although it is uncertain whether Fenton chemistry plays a substantial role in these diseases, or whether fructose 1,6-bis(phosphate) is capable of mitigating those effects.

References

External links

* {{DEFAULTSORT:Fructosebisphosphate16 Monosaccharide derivatives Organophosphates Glycolysis

In glycolysis

Isomerism

Iron chelation

See also

References

External links