- Dehydrogenase
- Classification:
- Cofactors:
- Classical members:
- Lactate dehydrogenase
- Alcohol dehydrogenase
- Glucose 6 phosphate dehydrogenase
- Pyruvate dehydrogenase
- Aldehyde dehydrogenase
- Succinate dehydrogenase
- Malate dehydrogenase
- Glutamate dehydrogenase
- Isocitrate dehydrogenase
- Glu/Leu/Phe/Val dehydrogenase
|
|
Nicotinamide adenine dinucleotide phosphate (NADP+) definition
Nicotinamide adenine dinucleotide phosphate or NADP+ is the cofactor for some dehydrogenases. NADP+ is the oxidised form of NADPH and vice versa, NADPH id the reduced form of NADP+.
Nicotinamide adenine dinucleotide phosphate (NADP+) basic
- Molecular formula: C21H29N7O17P3
- Molecular weight: 744.413 Da
- IUPAC name 1: 2'-O-phosphonoadenosine 5'-{3-[1-(3-carbamoylpyridinio)-1,4-anhydro-D-ribitol-5-yl] dihydrogen diphosphate}
- IUPAC name 2: [(2R,3R,4S,5S)-2-(6-aminopurin-9-yl)-5-[[[[(2S,3S,4R,5R)-5-(5-carbamoylpyridin-1-yl)-3,4-dihydroxy-oxolan-2-yl]methoxy-oxido-phosphoryl]oxy-hydroxy-phosphoryl]oxymethyl]-4-hydroxy-oxolan-3-yl]oxyphosphonic acid
- Appearance: White crystalline solid
Nicotinamide adenine dinucleotide phosphate (NADP+) structure
Different representation of the Nicotinamide adenine dinucleotide phosphate (NADP+) structure. All structures were derived from the NADP+ coordinates from the structure of Human Type I 17Beta-Hydroxysteroid Dehydrogenase complex with NADP and Estradiol (1A27.pdb). Click preview to see full resolution stereo picture.
Nicotinamide adenine dinucleotide phosphate (NADP+) synthesis pathway
In living organisms Nicotinamide adenine dinucleotide phosphate (NADP+) synthesised by one step from Nicotinamide adenine dinucleotide (NAD+). This reaction is catalyzed by NAD+ kinase EC 2.7.1.23 (systematic name - ATP:NAD+ 2'-phosphotransferase) with subsequent conversion of ATP to ADP.
|
NAD+ + ATP -> NADP+ + ADP catalyzed by NAD+ kinase, EC 2.7.1.23 (other names DPN kinase; nicotinamide adenine dinucleotide kinase (phosphorylating); nicotinamide adenine dinucleotide kinase; NADK)
Download ISIS Draw source file here
|
NADP+ and NADPH
The overall involvement of Nicotinamide adenine dinucleotide phosphate into the living cell processes is illustrated on Nicotinamide nucleotides in catabolism and biosynthesis scheme.
NADPH biosynthesis from NADP+
The major way of NADPH biosynthesis from NADP+ is the Pentose phosphate pathway (PPP). The pentose phosphate pathway is anaerobic generation of 5-carbon sugars from 6-carbon glucose. The main functions of these reactions are:
- Generation of NADPH from NADP+
- Generation of ribode-5-phosphate, used in nucleic acids and nucleotide biosynthesis
The pentose phosphate pathway consists from two main stages: oxidative and non-oxidative. NADP+ reduction to NADPH is take place only during oxidative stage of the pentose phosphate pathway.
|
Glucose 6-phosphate + NADP+ -> 6-phosphoglucono-D-lactone + NADPH + H+ catalysed by glucose 6-phosphate dehydrogenase, EC 1.1.1.49 (other names Zwischenferment; NADP-glucose-6-phosphate dehydrogenase; D-glucose 6-phosphate dehydrogenase; Entner-Doudoroff enzyme; NADP-dependent glucose 6-phosphate dehydrogenase; glucose-6-phosphate 1-dehydrogenase; G6PDH; glucose 6-phosphate dehydrogenase (NADP); GPD; 6-phosphoglucose dehydrogenase).
Systematic name: D-glucose-6-phosphate:NADP+ 1-oxidoreductase
Download ISIS Draw source file here
|
|
6-phospho-D-glucono-1,5-lactone + H2O -> 6-phospho-D-gluconate + H+ catalysed by 6-phosphogluconolactonase, EC 3.1.1.31 (other names: 6-PGL; phosphogluconolactonase).
Systematic name: 6-phospho-D-glucono-1,5-lactone lactonohydrolase
Download ISIS Draw source file here
|
|
6-phospho-D-gluconate + NADP+ -> D-ribulose 5-phosphate + CO2 + NADPH catalysed by phosphogluconate dehydrogenase (decarboxylating), EC 1.1.1.41 (other names: 6-phospho-D-gluconate dehydrogenase; 6-phosphogluconate dehydrogenase (decarboxylating); 6-phosphogluconic dehydrogenase; phosphogluconic acid dehydrogenase; 6-phosphogluconic carboxylase).
Systematic name: 6-phospho-D-gluconate:NADP+ 2-oxidoreductase (decarboxylating)
Download ISIS Draw source file here
|
The next step - conversion of Ribulose-5-phosphate to Ribose-5-phosphate by ribose-5-phosphate isomerase (D-ribose-5-phosphate aldose-ketose-isomerase, EC 5.3.1.6) or conversion of Ribulose-5-phosphate to Xylose-5-phosphate by ribulose-phosphate 3-epimerase (D-ribulose-5-phosphate 3-epimerase, EC 5.1.3.1) is belonging to the non-oxidative stage of Pentose phosphate pathway and will not be discussed here.
NADP+ biosynthesis from NADPH
NADPH is oxidized to NADP+ in many reaction in the living cells.
- In process of photosynthesis in the Calvin cycle of carbon fixation. The overall reaction for this cycle is:
- 6xNADPH => 6xNADP+ - NADPH oxidation
- 9xATP => 9xADP - energy reduction
- 3xCO2 + 5xH2O => C3H5O3PO32- + 2xH+ + 8xPi - carbon fixation
- Fatty acid synthesis:
- >C=O => >COOH catalyzed by (3R)-3-hydroxyacyl-[acyl-carrier-protein]:NADP+ oxidoreductase, EC 1.1.1.100 (Other names: 3-oxoacyl-[acyl-carrier-protein] reductase; NADPH-specific 3-oxoacyl-[acylcarrier protein]reductase; 3-oxoacyl-[ACP]reductase; 3-ketoacyl acyl carrier protein reductase; β-ketoacyl-acyl carrier protein reductase; β-ketoacyl thioester reductase; β-ketoacyl-ACP reductase;β-ketoacyl-[acyl-carrier protein](ACP) reductase;β-ketoacyl reductase;β-ketoacyl acyl carrier protein (ACP) reductase)
- -C=C- => -C-C- catalyzed by acyl-[acyl-carrier-protein]:NAD+ oxidoreductase, EC 1.3.1.9 (other names: enoyl-[acyl-carrier-protein] reductase (NADH2; enoyl-[acyl-carrier-protein] reductase (NADH); enoyl-[acyl carrier protein] reductase; NADH-specific enoyl-ACP reductase; NADH-enoyl acyl carrier protein reductase; enoyl-ACP reductase;)
Cholesterol biosynthesis (mevalonate pathway):
- -CO-S-CoA => -COH catalyzed by (R)-mevalonate:NADP+ oxidoreductase (CoA-acylating), EC 1.1.1.34 (other names: hydroxymethylglutaryl-CoA reductase (NADPH); hydroxymethylglutaryl-CoA reductase (NADPH2; 3-hydroxy-3-methylglutaryl CoA reductase (NADPH); HMGCoA reductase-mevalonate:NADP-oxidoreductase (acetylating-CoA); NADPH-hydroxymethylglutaryl-CoA reductase; S-3-hydroxy-3-methylglutaryl-CoA reductase; hydroxymethylglutaryl CoA reductase (NADPH); 3-hydroxy-3-methylglutaryl-CoA reductase; β-hydroxy-β-methylglutaryl coenzyme A reductase; hydroxymethylglutaryl coenzyme A reductase (reduced nicotinamide adenine dinucleotide phosphate); HMG-CoA reductase; HMGR)
|
