Dihydroxyacetone phosphate (DHAP, also glycerone phosphate in older texts) is the anion with the formula HOCH
2C(O)CH
2OPO
32-. This anion is involved in many
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 reac ...
s, including the
Calvin cycle in plants and
glycolysis.
[Nelson, D. L.; Cox, M. M. "Lehninger, Principles of Biochemistry" 3rd Ed. Worth Publishing: New York, 2000. .] It is the
phosphate ester of
dihydroxyacetone
Dihydroxyacetone (; DHA), also known as glycerone, is a simple saccharide (a triose) with formula .
DHA is primarily used as an ingredient in sunless tanning products. It is often derived from plant sources such as sugar beets and sugar cane, an ...
.
Role in glycolysis
Dihydroxyacetone phosphate lies in the glycolysis metabolic pathway, and is one of the two products of breakdown of
fructose 1,6-bisphosphate
Fructose 1,6-bisphosphate, also known as Harden-Young ester, is fructose sugar phosphorylated on carbons 1 and 6 (i.e., is a fructosephosphate). The β-D-form of this compound is common in cells. Upon entering the cell, most glucose and fructos ...
, along with
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 ...
. It is rapidly and reversibly isomerised to glyceraldehyde 3-phosphate.
''The numbering of the carbon atoms indicates the fate of the carbons according to their position in fructose 6-phosphate.''
Role in other pathways
In the
Calvin cycle, DHAP is one of the products of the sixfold reduction of
1,3-bisphosphoglycerate by NADPH. It is also used in the synthesis of sedoheptulose 1,7-bisphosphate and fructose 1,6-bisphosphate, both of which are used to reform ribulose 5-phosphate, the 'key' carbohydrate of the Calvin cycle.
DHAP is also the product of the dehydrogenation of
L-glycerol-3-phosphate, which is part of the entry of
glycerol
Glycerol (), also called glycerine in British English and glycerin in American English, is a simple triol compound. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic. The glycerol backbone is found in lipids known ...
(sourced from
triglycerides
A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids (from ''tri-'' and ''glyceride'').
Triglycerides are the main constituents of body fat in humans and other vertebrates, as we ...
) into the
glycolytic pathway
Glycolysis is the metabolic pathway that converts glucose () into pyruvic acid, pyruvate (). The Thermodynamic free energy, free energy released in this process is used to form the high-energy molecules adenosine triphosphate (ATP) and NADH, red ...
. Conversely, reduction of glycolysis-derived DHAP to L-glycerol-3-phosphate provides adipose cells with the activated glycerol backbone they require to synthesize new triglycerides. Both reactions are catalyzed by the enzyme
glycerol 3-phosphate dehydrogenase with
NAD+/NADH as cofactor.
DHAP also has a role in the ether-lipid biosynthesis process in the protozoan parasite ''
Leishmania mexicana
''Leishmania mexicana'' belongs to the '' Leishmania'' genus and is the causal agent of cutaneous leishmaniasis in Mexico and central America.
''Leishmania mexicana'' is an obligate intracellular protozoan parasite that causes the cutaneous f ...
''.
DHAP is a precursor to 2-oxopropanal. This conversion is the basis of a potential biotechnological route to the commodity chemical
1,2-propanediol.
See also
*
Dihydroxyacetone
Dihydroxyacetone (; DHA), also known as glycerone, is a simple saccharide (a triose) with formula .
DHA is primarily used as an ingredient in sunless tanning products. It is often derived from plant sources such as sugar beets and sugar cane, an ...
*
Glycerol 3-phosphate shuttle
The glycerol-3-phosphate shuttle is a mechanism that regenerates NAD+ from NADH, a by-product of glycolysis. The shuttle consists of the sequential activity of two proteins: GPD1 which transfers an electron pair from NADH to dihydroxyacetone phosp ...
References
{{Glycolysis
Photosynthesis
Alpha-hydroxy ketones
Organophosphates
Phosphate esters
Glycolysis