EC Number   |
Reaction |
Reference |
|---|
    1.2.1.12 | D-glyceraldehyde 3-phosphate + phosphate + NAD+ = 3-phospho-D-glyceroyl phosphate + NADH + H+ |
B-specific oxidoreductase |
287927 |
| 1.2.1.12 | D-glyceraldehyde 3-phosphate + phosphate + NAD+ = 3-phospho-D-glyceroyl phosphate + NADH + H+ |
bi-uni-uni-uni-ping-pong mechanism in which NAD+ and phosphate interact sequentially with the enzyme, followed in turn by the release of 3-phospho-D-glyceroyl phosphate, the addition of D-glyceraldehyde-3-phosphate, and the release of NADH. At pH 7.2, NAD+ binds to the enzyme in a rapid-equilibrium fashion, whereas at pH 8.8 there is rapid-equilibrium addition of both NAD+ and phosphate to the enzyme |
287920 |
| 1.2.1.12 | D-glyceraldehyde 3-phosphate + phosphate + NAD+ = 3-phospho-D-glyceroyl phosphate + NADH + H+ |
GAPDH-catalyzed phosphorylation of D-G3H takes place in two steps. In the first exergonic reaction the aldehyde group of D-glyceraldehyde 3-phosphate is converted into a carboxylic acid with concomitant reduction of NAD+ to NADH. The energy released by this reaction drives the endergonic second reaction in which a molecule of inorganic phosphate is transferred to the intermediate acid to form the product 3-phospho-D-glyceroyl phosphate. The reaction mechanism involves formation of a covalent bond between the thiol group of a conserved cysteine residue of GAPDH and the carbonyl C-atom of D-glyceraldehyde 3-phosphate resulting in the formation of the hemithioacetal intermediate. A hydride ion is transferred from D-glyceraldehyde 3-phosphate to the cofactor NAD+ to form NADH while oxidation of D-glyceraldehyde 3-phosphate by a water molecule generates a thioester intermediate. In the second step, the thioester is phosphorylated in a nucleophilic attack by an inorganic phosphate ion resulting in the formation of the product 3-phospho-D-glyceroyl phosphate and the release of the thiol-group of the active site cysteine |
743613 |
| 1.2.1.12 | D-glyceraldehyde 3-phosphate + phosphate + NAD+ = 3-phospho-D-glyceroyl phosphate + NADH + H+ |
ordered ter bi mechanism characterized by the sequential addition of NAD+, glyceraldehyde 3-phosphate and phosphate to the enzyme and the sequential release of 3-phospho-D-glyceroyl phosphate and NADH from the enzyme |
287945 |
| 1.2.1.12 | D-glyceraldehyde 3-phosphate + phosphate + NAD+ = 3-phospho-D-glyceroyl phosphate + NADH + H+ |
the conserved residue C158 is responsible for nucleophilic catalysis and the conserved residue H185 acts as a catalytic base. The enzyme exhibits a kinetic mechanism in which first NAD+, then D-glyceraldehyde 3-phosphate bind to the active site resulting in the formation of a covalently bound thiohemiacetal intermediate. After oxidation of the thiohemiacetal and subsequent nucleotide exchange (NADH off, NAD+ on), the binding of inorganic phosphate and phosphorolysis yields the product 3-phospho-D-glyceroyl phosphate. Solvent and multiple kinetic isotope effects revealed that the first halfreaction is rate limiting and utilizes a step-wise mechanism for thiohemiacetal oxidation via a transient alkoxide to promote hydride transfer and thioester formation |
-, 741758 |
