Glyceraldehyde-3-phosphate dehydrogenase (NADP+)
|Glyceraldehyde-3-phosphate dehydrogenase (NADP+)|
|PDB structures||RCSB PDB PDBe PDBsum|
|Gene Ontology||AmiGO / QuickGO|
Glyceraldehyde-3-phosphate dehydrogenase (NADP+) (EC 22.214.171.124) (GAPN) is an enzyme that irreversibly catalyzes the oxidation of glyceraldehyde-3-phosphate (GAP) to 3-phosphoglycerate (3-PG or 3-PGA) using the reduction of NADP+ to NADPH. GAPN is used in a variant of glycolysis that conserves energy as NADPH rather than as ATP. The NADPH and 3-PG can then be used for synthesis. The most familiar variant of glycolysis uses glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and phosphoglycerate kinase to produce ATP. GAPDH is phosphorylating. GAPN is non-phosphorylating.
Glyceraldehyde-3-phosphate dehydrogenase (NADP+) catalyzes
- GAP + NADP+ + H2O → 3-PG + NADPH + H+
- GAP + NAD+ + Pi ⇌ 1,3-bisphosphoglycerate + NADH + H+
- 1,3-bisphosphoglycerate + ADP ⇌ 3-PG + ATP
Usually [NADPH] / [NADP+] >> 1 >> [NADH] / [NAD+].
- Rosenberg LL, Arnon DI (1955). "The preparation and properties of a new glyceraldehyde-3-phosphate dehydrogenase from photosynthetic tissues". J. Biol. Chem. 217 (1): 361–71. PMID 13271400.
- Boyd DA, Cvitkovitch DG, Hamilton IR (1995). "Sequence, expression, and function of the gene for the nonphosphorylating, NADP-dependent glyceraldehyde-3-phosphate dehydrogenase of Streptococcus mutans". J. Bacteriol. 177 (10): 2622–7. PMC 176930. PMID 7751269.