Many translated example sentences containing “malato deshidrogenasa” – English-Spanish dictionary and search engine for English translations. Malato deshidrogenasa citosólica de hígado de cobayo: interferencias cinéticas de la lactato deshidrogenasa y resolución de la multiplicidad del enzima. Malato deshidrogenasa descarboxilante inducible en lactobacilos homofermentativos []. Oliver, G. Pesce de Rutz Holgado, A.A. Benito de Cardenas, I.L.

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Malate dehydrogenase EC 1. This reaction is part of many metabolic pathwaysincluding the citric acid cycle. Several isozymes of malate dehydrogenase exist.

There are two main isoforms in eukaryotic cells. The other is found in the cytoplasmassisting the malate-aspartate shuttle with exchanging reducing equivalents so that malate can pass through the mitochondrial membrane to be transformed into oxaloacetate for further cellular processes. The malate dehydrogenase family contains L-lactate dehydrogenase and Lhydroxyisocaproate dehydrogenases.

L-lactate deshidrogeenasa catalyzes the conversion of L-lactate to pyruvatethe last step in anaerobic glycolysis. In most organisms, malate dehydrogenase MDH exists as a homodimeric molecule and is closely related to amlato dehydrogenase Deshirdogenasa in dsshidrogenasa.

It is a large protein molecule with subunits weighing between 30 and 35 kDa. This indicates that there is a possible evolutionary linkage between lactate dehydrogenase and malate dehydrogenase. Each subunit of the malate dehydrogenase dimer has two distinct domains that vary in structure and functionality. The subunits are held together through extensive hydrogen-bonding and hydrophobic interactions.

Malate dehydrogenase has also been shown to have a mobile loop region that plays a crucial role in the enzyme’s catalytic activity. Studies have shown that conformational change of this loop region from the open conformation to the closed conformation after binding of substrate enhances MDH catalysis through shielding of substrate and catalytic amino acids from solvent. Studies have also indicated that this loop maoato is highly conserved in malate dehydrogenase. In its active state, MDH undergoes a conformational change that encloses the substrate to minimize solvent exposure and to position key residues in closer proximity to the substrate.

This oxidation step results in the elimination of a proton and a hydride ion from the substrate. This electrostatic stabilization helps facilitate the transfer of the proton. Additionally, the Arginine residues on the enzyme provide additional substrate specificity and binding through hydrogen bonding between the guanidinium side chain of the Arginine amino acid residues and the carboxylates of the substrate.

Studies have also identified a mobile loop in malate dehydrogenase that participates in the catalytic activity of the enzyme. The loop undergoes a conformational change to shield the substrate and catalytic amino acids from the solvent in response to the binding of the malate dehydrogenase: This flipping of the loop to the deshidroggenasa position to cover the active site also promotes enhanced interaction dewhidrogenasa the catalytically important amino residues on the enzyme with the substrate.


Additionally, the movement of the loop has been shown to correlate with the rate determining step of the deshidrogenaxa. Malate dehydrogenases catalyzes the interconversion of malate to oxaloacetate. Malate dehydrogenase is also involved in gluconeogenesisthe synthesis of desshidrogenasa from smaller molecules.

Pyruvate in the mitochondria is acted upon by pyruvate carboxylase to form oxaloacetate, a citric acid cycle intermediate.

In order to get the oxaloacetate out of the mitochondria, malate dehydrogenase reduces it to malate, deshldrogenasa it then traverses the inner mitochondrial membrane. Once in the cytosol, the malate is oxidized back to oxaloacetate by cytosolic malate dehydrogenase. Kinetic studies show that malate dehydrogenase enzymatic activity is ordered.

Malate dehydrogenase

The Kcat value is Additionally, pH levels control specificity of substrate binding by malate dehydrogenase due to proton transfer in the catalytic mechanism.

Studies have indicated that the binding of the enol form oxaloacetate with the malate dehydrogenase: NADH complex forms much more dwshidrogenasa at higher pH values. Consequently, the non-protonated form malate dehydrogenase binds preferentially to L-malate and the enol form of oxaloacetate. In contrast, D-malate, hydroxymalonate, and the keto form of oxaloacetate have been found to bind exclusively to the protonated form of the enzyme.

Specifically, when the histidine is protonated, the His residue can form a hydrogen bond with the substrate’s carbonyl oxygen, which shifts electron density away from the oxygen and makes it more susceptible to nucleophilic attack by hydride. This promotes the mlaato of malate dehydrogenase to these substrates.

As a result, at mwlato pH values malate dehydrogenase binds preferentially to D-malate, hydroxymalonate, and keto-oxaloacetate. This may be due to deviations observed in the kinetic behavior of malate dehydrogenase at high oxaloacetate and L-malate concentrations.

Experiments have shown that Citrate can both allosterically activate and inhibit the enzymatic activity of malate dehydrogenase. Although malate dehydrogenase is typically considered a reversible enzyme, it is believed that deshirrogenasa is an allosteric regulatory site on the enzyme where citrate can bind to and drive the reaction equilibrium in either direction.

Glutamate has also been shown to inhibit malate dehydrogenase activity. Furthermore, it has been shown that alpha ketogluturate dehydrogenase can interact with mitochondrial aspartate aminotransferase to form a complex, which can then bind to malate dehydrogenase, forming a ternary complex that reverses inhibitory action on malate dehydrogenase enzymatic activity by glutamate.

Additionally, the formation of this complex enables glutatmate to react with aminotransferase without interfering activity of malate dehydrogenase. The formation of this ternary complex also facilitates the release of oxalocetate from malate dehydrogenase to aminotransferase. Kinetically, the binding of malate dehydrogenase to the binary complex of alpha ketogluturate dehydrogenase and aminotrannferase has been shown to increase reaction rate of malate dehydrogenase because the Km of malate dehydrogenase is decreased when it is bound as part of this complex.


Click on genes, proteins and metabolites below to link to respective articles. From Wikipedia, the free encyclopedia. For other uses, see Malate dehydrogenase disambiguation. General Physiology and Biophysics. Journal of Molecular Biology. Journal of Molecular Evolution. Trends in Biochemical Sciences. A complex of deshidrovenasa apoenzyme and citrate at 1. Life at the Molecular Level 4th ed. Mxlato Journal of Biological Chemistry. Biochemical and Biophysical Research Communications.

Randell; Deshidrogwnasa, Allison B. Mendelian inherited electrophoretic variants in the mouse”. Kinetics and deshidrogdnasa of reassociation”. A kinetic investigation of the reaction mechanism and a comparison with lactate dehydrogenase”.

Reactivity of sulfhydryl groups and conformation of the supernatant enzyme”. Biochimica et Biophysica Acta. D-lactate dehydrogenase cytochrome D-lactate malayo cytochrome c Mannitol dehydrogenase cytochrome. Glucose oxidase L-gulonolactone oxidase Deshidrogenass oxidase.

malaato Vitamin K epoxide reductase Vitamin-K-epoxide reductase warfarin-insensitive. Malate dehydrogenase quinone Quinoprotein glucose dehydrogenase. Citric acid cycle enzymes.

Pyruvate dehydrogenase complex E1E2E3 regulated by Pyruvate dehydrogenase kinase and Pyruvate dehydrogenase phosphatase.

Pyruvate carboxylase Aspartate transaminase. Alternative oxidase Electron-transferring-flavoprotein dehydrogenase. Carnitine palmitoyltransferase I Long-chain-fatty-acid—CoA ligase. Adenylate kinase Creatine kinase. Malate-aspartate shuttle Glycerol phosphate shuttle.

Malate dehydrogenase – Wikipedia

Citrate synthase Aconitase Isocitrate dehydrogenase Oxoglutarate dehydrogenase complex Succinyl coenzyme A synthetase Fumarase Malate dehydrogenase.

Aspartate transaminase Glutamate dehydrogenase Pyruvate amlato complex. Carbamoyl phosphate synthetase I Ornithine transcarbamylase N-Acetylglutamate synthase. Cholesterol side-chain cleavage enzyme Steroid beta-hydroxylase Aldosterone synthase Frataxin. Mitochondrial membrane transport protein Mitochondrial permeability transition pore Mitochondrial carrier.

Allosteric regulation Cooperativity Enzyme inhibitor Enzyme activator. EC number Enzyme superfamily Enzyme family List of enzymes. Molecular and Cellular Biology portal. Retrieved from ” https: Genes on human chromosome 2 Genes on human chromosome 7 EC 1.

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In other projects Wikimedia Commons. This page was last edited on 3 Aprilat By using this site, you agree to the Terms of Use and Privacy Policy. Structure of the protein with attached cofactors.