Glycerol-3-phosphate dehydrogenase

Glycerol-3-phosphate dehydrogenase (GPDH) is an nicotinamide adenine dinucleotide-dependent enzyme that catalyzes the oxidation of sn-glycerol 3-phosphate to dihydroxyacetone phosphate (aka glycerone phosphate, outdated).

Older terms for glycerol-3-phosphate dehydrogenase include alpha glycerol-3-phosphate dehydrogenase (alphaGPDH) and glycerolphosphate dehydrogenase (GPDH). However, glycerol-3-phosphate dehydrogenase is not the same as Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) whose substrate is an aldehyde not an alcohol.

Glycerol-3-phosphate shuttle
The cytosolic together with the mitochondrial glycerol-3-phosphate dehydrogenase allow regeneration of oxidized nicotinamide adenine dinucleotide (NAD+) from its reduced form NADH. NADH is produced during glycolysis. The two GPDH enzymes work together to restore NAD+ and feed the electrons into the mitochondrial respiratory chain. Illustrated here.