Enzyme involved in the production of energy by cells
Glucose-6-phosphate dehydrogenase (G6PD or G6PDH) (EC 1.1.1.49) is a cytosolic enzyme that catalyzes the chemical reaction
- D-glucose 6-phosphate + NADP+ + H2O ⇌ 6-phospho-D-glucono-1,5-lactone + NADPH + H+
This enzyme participates in the pentose phosphate pathway (see image), a metabolic pathway that supplies reducing energy to cells (such as erythrocytes) by maintaining the level of the reduced form of the co-enzyme nicotinamide adenine dinucleotide phosphate (NADPH). The NADPH in turn maintains the level of glutathione in these cells that helps protect the red blood cells against oxidative damage from compounds like hydrogen peroxide.[1] Of greater quantitative importance is the production of NADPH for tissues involved in biosynthesis of fatty acids or isoprenoids, such as the liver, mammary glands, adipose tissue, and the adrenal glands. G6PD reduces NADP+ to NADPH while oxidizing glucose-6-phosphate.[2] Glucose-6-phosphate dehydrogenase is also an enzyme in the Entner–Doudoroff pathway, a type of glycolysis.
Clinically, an X-linked genetic deficiency of G6PD makes a human prone to non-immune hemolytic anemia.[3]