Glyceraldehyde-3-phosphate dehydrogenase (NADP+) (EC 1.2.1.9) (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+) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 1.2.1.9 | ||||||||
| CAS no. | 9028-92-6 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
GAPN was reported first by Rosenberg and Arnon in 1954.[1] It has been found in plants, algae, and bacteria.[2]
Reactions
editGlyceraldehyde-3-phosphate dehydrogenase (NADP+) catalyzes
- GAP + NADP+ + H2O → 3-PG + NADPH + H+
Glyceraldehyde-3-phosphate dehydrogenase and phosphoglycerate kinase catalyze
- GAP + NAD+ + Pi ⇌ 1,3-bisphosphoglycerate + NADH + H+
- 1,3-bisphosphoglycerate + ADP ⇌ 3-PG + ATP
Usually [NADPH] / [NADP+] >> 1 >> [NADH] / [NAD+].
See also
editReferences
edit- ^ 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.
