Kinetic formulations for the oxidation and the reduction of glyoxylate by lactate dehydrogenase.
Biochimica et biophysica acta
confidence
Key findings
Enzyme kinetics study of LDH-catalyzed oxidation/reduction of glyoxylate with NAD+; no clinical or biological endpoints reported.
View source on PubMed (PMID 13838) ↗
- Sample size
- N/A
- Population
- In vitro enzymatic study (chicken liver lactate dehydrogenase)
- Dosing
- N/A
- Duration
- N/A
- Route
- in vitro
- Blinding
- not_reported
- Controls
- none
- Drug class
- coenzyme
Full abstract
Chicken liver lactate dehydrogenase (L-lactate : NAD+ oxidoreductase, EC 1.1.1.27) irreversibly catalyses the oxidation of glyoxylate (hydrated form) (I) to oxalate (pH = 9.6) and the reduction of (non-hydrated form) (II) to glycolate (pH = 7.4). (I) attaches to the enzyme in the pyruvate binding site and (II) attaches to the enzyme at the L-lactate binding site. The oxidation of (I) (pH = 9.6) is adapted to the following mechanism: (see book). The abortive complexes, E-NADH-I and E-NAD+-II, are responsible for the inhibition by excess substrate in the reduction and oxidation systems, respectively. When lactate dehydrogenase and NAD+ are preincubated, E-NAD+- NAD+ appears and causes inhibition by excess NAD+ in the glyoxylate-lactate dehydrogenase-NAD+ and L-lactate-lactate dehydrogenase-NAD+ systems; the second NAD+ molecule attaches to the enzyme at the L-lactate binding site.