gliserol3fosfat

Gliserol-3-fosfat, commonly known as glycerol-3-phosphate (G3P), is a phosphorylated derivative of glycerol and a central metabolite in carbohydrate and lipid metabolism. Its chemical structure consists of a three-carbon glycerol backbone with a phosphate group esterified to the third carbon. The molecule is chiral at the middle carbon and exists as stereoisomers; the sn-glycerol-3-phosphate form is the one typically used in glycerophospholipid biosynthesis.

Biosynthesis and metabolism: In cells, G3P is mainly produced by the reduction of dihydroxyacetone phosphate (DHAP) via glycerol-3-phosphate dehydrogenase, using NADH as a cofactor. It can be oxidized back to DHAP by mitochondrial glycerol-3-phosphate dehydrogenase as part of the glycerol phosphate shuttle, which transfers reducing equivalents to the mitochondrial electron transport chain. G3P also serves as the backbone for acylation by glycerol-3-phosphate acyltransferases, forming lysophosphatidic acid and then phosphatidic acid, key intermediates in the biosynthesis of glycerolipids such as phospholipids and triglycerides.

Biological significance: G3P links carbohydrate and lipid metabolism and provides the glycerol backbone for glycerophospholipid biosynthesis in the endoplasmic reticulum. In bacteria and other organisms, it participates in membrane lipid synthesis and related pathways. Beyond lipid synthesis, G3P participates in metabolic shuttles that balance cytosolic and mitochondrial redox states, integrating energy and lipid metabolism.