Table of Contents
Where is malate dehydrogenase found?
mitochondria
Malate dehydrogenase (MDH) is a predominately periportal enzyme that is expressed highly in the extra-mitochondrial cytoplasm of the liver, although 10% of MDH has been reported in the mitochondria [23]. It is an enzyme in the citric acid cycle that catalyzes the reversible conversion of malate into oxaloacetate.
What does malate dehydrogenase do?
Malate dehydrogenase (MDH) is an enzyme widely distributed among living organisms and is a key protein in the central oxidative pathway. It catalyzes the interconversion between malate and oxaloacetate using NAD+ or NADP+ as a cofactor.
When was malate dehydrogenase discovered?
1910
Malate dehydrogenase, MDH, (l–Malate: NAD oxidoreductase, EC 1.1. 1.37) was discovered by Thunberg1 and Batelli and Stern2 in 1910, and isolated in pure state from pig heart by Straub3. The enzyme occurs in animal and plant tissues and in microorganisms.
Do humans have malate dehydrogenase?
MDH1 malate dehydrogenase 1 [ (human)] Data show that in the endogenous readthrough of the human MDH1 stop codon, the stop codon can encode tryptophan and arginine, and is tissue-specific. Proliferating cells rely on both MDH1 and LDH to replenish cytosolic NAD.
Why is MDH important?
Malate dehydrogenase (MDH), a key enzyme in the tricarboxylic acid cycle (TCA), plays important metabolic roles in aerobic energy producing pathways and in malate shuttle (Figure 1) [5]. The enzyme is widely distributed in animals, higher plants, and microorganisms.
Is malate dehydrogenase used in gluconeogenesis?
Malate dehydrogenase is also involved in gluconeogenesis, the synthesis of glucose from smaller molecules. Pyruvate in the mitochondria is acted upon by pyruvate carboxylase to form oxaloacetate, a citric acid cycle intermediate.
Is malate dehydrogenase reversible?
Malate Dehydrogenase: Regulation. Malate dehydrogenase is allosterically regulated. The oxidation of malate into oxaloacetate is a reversible reaction. Production of oxaloacetate is stimulated by high concentrations of malate, while high concentrations of oxaloacetate inhibits the reaction.
How is malate dehydrogenase regulated?
Why do cells need malate dehydrogenase to perform gluconeogenesis?
What is malate dehydrogenase activated by?
Malate dehydrogenase is specifically activated by citrate in the NAD+ —> NADH (malate —> oxaloacetate) direction and inhibited by citrate in the NADH —> NAD+ (oxaloacetate —> malate) direction. Citrate doesn’t bind at the enzymes catalytic site but instead binds at a secondary or regulatory site.