Glycerol 3-phosphate

sn-Glycerol 3-phosphate is a phosphoric ester of glycerol, which is a component of glycerophospholipids. Equally appropriate names in biochemical context include glycero-3-phosphate, 3-O-phosphonoglycerol, 3-phosphoglycerol; and Gro3P. From a historical reason, it is also known as L-glycerol 3-phosphate, D-glycerol 1-phosphate, L-α-glycerophosphoric acid. It should not be confused with the similarly named glycerate 3-phosphate or glyceraldehyde 3-phosphate. sn-Glycerol 3-phosphate is a phosphoric ester of glycerol, which is a component of glycerophospholipids. Equally appropriate names in biochemical context include glycero-3-phosphate, 3-O-phosphonoglycerol, 3-phosphoglycerol; and Gro3P. From a historical reason, it is also known as L-glycerol 3-phosphate, D-glycerol 1-phosphate, L-α-glycerophosphoric acid. It should not be confused with the similarly named glycerate 3-phosphate or glyceraldehyde 3-phosphate. Glycerol 3-phosphate is synthesized by reducing dihydroxyacetone phosphate (DHAP), a glycolysis intermediate, with glycerol-3-phosphate dehydrogenase. DHAP and thus glycerol 3-phosphate is also possible to be synthesized from amino acids and citric acid cycle intermediates via glyceroneogenesis pathway. It is also synthesized by phosphorylating glycerol generated upon hydrolyzing fats with glycerol kinase, and can feed into glycolysis or gluconeogenesis pathways. Glycerol 3-phosphate is a starting material for de novo synthesis of glycerolipids. In eukaryotes, it is first acylated on its sn-1 position by an ER- or mitochondrial membrane enzyme, glycerol-3-phosphate O-acyltransferase, and another acyl group is then added on the sn-2 position making phosphatidic acids. Glycerol-1-phosphatase removes the phosphate group of glycerol 3-phosphate to generate glycerol, allowing glycerol fermentation to produce glycerol from glucose through glycolysis pathway. A number of microbes, plants and mammals have been shown to express this enzyme. Glycerol-3-phosphate dehydrogenases are located both in the cytosol and the intermembrane face of mitochondrial inner membrane. Glycerol 3-phosphate (G3P) and dihydroxyacetone phosphate (DHAP) are molecules so small that they can permeate the mitochondrial outer membrane through porins and shuttle between two dehydrogenases. Using this shuttle system, NADH generated by cytosolic metabolisms including glycolysis is reoxidized to NAD+ reducing DHAP to G3P, and the reducing equivalent can be used for generating a proton gradient across the mitochondrial inner membrane by coupling and oxidizing G3P and reducing quinone. Glycerol 1-phosphate, sometimes called as D-glycerol 3-phosphate, is an enantiomer of glycerol 3-phosphate. Most organisms use 3-phosphate, or L-configuration, for glycerolipid backborn; however, 1-phosphate is specifically used in archeal ether lipids.