Merck, 10127914001, L-Malate Dehydrogenase (L-MDH)

General description
L-malate:NAD⁺ oxidoreductase
The L-malate dehydrogenase enzyme is a nuclear gene product that is synthesized with a 24-residue amino-terminal signal peptide. This peptide is proteolytically cleaved during the translocation of the enzyme to the mitochondrial matrix.
Application
The enzyme L-malate dehydrogenase from pig heart has been used to measure PEPCK (phosphoenolpyruvate carboxykinase) activity. The oxaloacetate, produced by PEPCK, is reduced to malate via the oxidation of NADH, which in turn is measured at 340 nm using a spectrophotometer. The enzyme has also been used to measure oxaloacetate by measuring the reduction in NADH spectroscopically at 340 nm.
Biochem/physiol Actions
The enzyme L-malate dehydrogenase from pig heart catalyzes the oxidation of L-malate to oxaloacetate. The enzyme is an NAD-dependent mitochondrial dehydrogenase that functions in the tricarboxylic acid cycle. It is a component of the malate-aspartate shuttle that transports reducing equivalents across the inner mitochondrial membrane in the form of malate.
Physical form
Solution in 50% glycerol (v/v), pH approximately 7
Suspension in 3.2 M ammonium sulfate solution, pH approximately 6
Preparation Note
Activator: – phosphate
– arsenate
– Mg²⁺
– Zn²⁺
Analysis Note
Contaminants: <0.002% GOT, <0.01% fumarase and LDH, each luM each, <0.02% HK, <0.002% PGI
Other Notes
For life science research only. Not for use in diagnostic procedures.