Organization of Krebs tricarboxylic acid cycle enzymes

Robinson, J. B. D.; Srere, Paul A.

doi:10.1016/0006-2944(85)90023-7

Cited by 41 publications

(44 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, in these same mitochondrial preparations it could be shown that the state 3 rate of 02 uptake in the presence of glycine could be markedly increased by the addition of a second NAD-linked substrate such as malate (3,5). Thus, these data also support the hypothesis that the malate-oxidizing enzymes in leaf mitochondria have The concept of spatial organization of enzymes within the mitochondrial matrix is already well established for animal mitochondria (2,14,21,23). By the use of gentle disruption techniques, Robinson and Srere (21) have been able to demonstrate that TCA cycle enzymes are not randomly distributed within the matrix but are probably organized into a functional complex of enzymes (a metabolon) associated with the inner surface of the inner mitochondrial membrane.…”

Section: Discussionsupporting

confidence: 61%

Evidence for Metabolic Domains within the Matrix Compartment of Pea Leaf Mitochondria

Wiskich¹,

Bryce²,

Day³

et al. 1990

Plant Physiol.

View full text Add to dashboard Cite

The simultaneous oxidation of malate and of glycine was investigated in pea (Pisum sativum) leaf mitochondria. Adding malate to state 4 glycine oxidation did not inhibit, and under some conditions stimulated, glycine oxidation. State 4 oxygen uptake with glycine is restricted because of the control exerted by the membrane potential but reoxidation of NADH by oxaloacetate reduction can still occur. Thus, malate addition stimulates glycine metabolism by producing oxaloacetate. The malate dehydrogenase (EC 1.1.1.37) enzyme fraction remote from glycine decarboxylase (EC 2.1.2.10) oxidizes malate whereas that closely associated with it produces malate, i.e. they function in opposite directions. It to cope with both the large amount of NADH produced by glycine decarboxylase and the concomitant contribution of reducing equivalents from the TCA4 cycle which also appears to be operational in leaf mitochondria in the light (1 1

show abstract

Section: Discussionsupporting

confidence: 61%

Evidence for Metabolic Domains within the Matrix Compartment of Pea Leaf Mitochondria

Wiskich¹,

Bryce²,

Day³

et al. 1990

Plant Physiol.

View full text Add to dashboard Cite

show abstract

“…Investigation of the optimum pH for m-MDH activity in the oxaloacetate reductase direction was performed with 200 lM oxaloacetate and 200 lM NADH over a wide pH range (4)(5)(6)(7)(8)(9)(10)(11)(12) and at 30°C. Determination of the pH optimum in the malate oxidation direction was achieved with 10 mM malate and 1 mM NAD + as substrate and cosubstrate, respectively, over the same pH range at 30°C.…”

Section: Determination Of Selected Biochemical Propertiesmentioning

confidence: 99%

“…Mitochondrial MDH displays a complex regulatory pattern that involves allosteric activation [2], membrane interaction [3] and formation of multienzyme complexes [4] with enzymes such as citrate synthase, aspartate aminotransferase and other mitochondrial components [5][6][7][8][9][10]. Much of the previous research has focused on the comparison of primary and three-dimensional structures of mitochondrial and cytoplasmic forms of MDH isolated from a single source, e.g.…”

mentioning

confidence: 99%

Mitochondrial malate dehydrogenase from the thermophilic, filamentous fungusTalaromyces emersonii

Maloney

Callan

Murray

et al. 2004

European Journal of Biochemistry

View full text Add to dashboard Cite

Mitochondrial malate dehydrogenase (m-MDH; EC 1.1.1.37), from mycelial extracts of the thermophilic, aerobic fungus Talaromyces emersonii, was purified to homogeneity by sequential hydrophobic interaction and biospecific affinity chromatography steps. Native m-MDH was a dimer with an apparent monomer mass of 35 kDa and was most active at pH 7.5 and 52°C in the oxaloacetate reductase direction. Substrate specificity and kinetic studies demonstrated the strict specificity of this enzyme, and its closer similarity to vertebrate m-MDHs than homologs from invertebrate or mesophilic fungal sources. The fulllength m-MDH gene and its corresponding cDNA were cloned using degenerate primers derived from the N-terminal amino acid sequence of the native protein and multiple sequence alignments from conserved regions of other m-MDH genes. The m-MDH gene is the first oxidoreductase gene cloned from T. emersonii and is the first full-length m-MDH gene isolated from a filamentous fungal species and a thermophilic eukaryote. Recombinant m-MDH was expressed in Escherichia coli, as a His-tagged protein and was purified to apparent homogeneity by metal chelate chromatography on an Ni 2+ -nitrilotriacetic acid matrix, at a yield of 250 mg pure protein per liter of culture. The recombinant enzyme behaved as a dimer under nondenaturing conditions. Expression of the recombinant protein was confirmed by Western blot analysis using an antibody against the His-tag. Thermal stability studies were performed with the recombinant protein to investigate if results were consistent with those obtained for the native enzyme.Keywords: malate dehydrogenase; filamentous fungus; bio-specific affinity chromatography; thermophilic eukaryote; Talaromyces emersonii.Malate dehydrogenase (MDH) catalyzes the pyridine nucleotide-dependent interconversion of malate and oxaloacetate in the tricarboxylic acid cycle. It is also thought to have a role in the malate/aspartate shuttle across the inner mitochondrial membrane. In most eukaryotic cells there are two major isoenzymes of MDH, cytosolic MDH (c-MDH) and mitochondrial MDH (m-MDH) [1].The majority of m-MDHs isolated to date from eukaryotic sources are homodimers of identical subunits, with a monomer size of 34 kDa. Mitochondrial MDH displays a complex regulatory pattern that involves allosteric activation [2], membrane interaction [3] and formation of multienzyme complexes [4] with enzymes such as citrate synthase, aspartate aminotransferase and other mitochondrial components [5][6][7][8][9][10]. Much of the previous research has focused on the comparison of primary and three-dimensional structures of mitochondrial and cytoplasmic forms of MDH isolated from a single source, e.g. pig heart tissue [11,12]. In contrast to bacterial, vertebrate and invertebrate m-MDH, a paucity of information exists on fungal m-MDH with significantly more known about yeast m-MDH than homologs from filamentous fungal species. Previous research by Dalhaus et al. [13] and Goward and Nicholls [14] has proposed that investigation...

show abstract

“…Furthermore, when its FeS center is oxidized by superoxide, Fe 3+ is released and this unprotected, free iron ion can trigger a Fenton reaction causing damage to proteins in its proximity. Since the Krebs cycle appears organized in a metabolon in the matrix, 53 it is reasonable to find others Krebs cycle enzymes to be carbonylated under oxidative stress because of the proximity of aconitase. Indeed, we found carbonylated malate dehydrogenase and 2-oxoglutarate dehydrogenase.…”

Section: ■ Discussion and Conclusionmentioning

confidence: 99%

Profiling Carbonylated Proteins in Heart and Skeletal Muscle Mitochondria from Trained and Untrained Mice

Carpentieri¹,

Gamberi

Modesti

et al. 2016

J. Proteome Res.

View full text Add to dashboard Cite

Understanding the relationship between physical exercise, reactive oxygen species, and skeletal muscle modification is important in order to better identify the benefits or the damages that appropriate or inappropriate exercise can induce. Heart and skeletal muscles have a high density of mitochondria with robust energetic demands, and mitochondria plasticity has an important role in both the cardiovascular system and skeletal muscle responses. The aim of this study was to investigate the influence of regular physical activity on the oxidation profiles of mitochondrial proteins from heart and tibialis anterior muscles. To this end, we used the mouse as animal model. Mice were divided into two groups: untrained and regularly trained. The carbonylated protein pattern was studied by two-dimensional gel electrophoresis followed by Western blot with anti-dinitrophenyl hydrazone antibodies. Mass spectrometry analysis allowed the identification of several different protein oxidation sites, including methionine, cysteine, proline, and leucine residues. A large number of oxidized proteins were found in both untrained and trained animals. Moreover, mitochondria from skeletal muscles and heart showed almost the same carbonylation pattern. Interestingly, exercise training seems to increase the carbonylation level mainly of mitochondrial proteins from skeletal muscle.

show abstract

Organization of Krebs tricarboxylic acid cycle enzymes

Cited by 41 publications

References 9 publications

Evidence for Metabolic Domains within the Matrix Compartment of Pea Leaf Mitochondria

Evidence for Metabolic Domains within the Matrix Compartment of Pea Leaf Mitochondria

Mitochondrial malate dehydrogenase from the thermophilic, filamentous fungusTalaromyces emersonii

Profiling Carbonylated Proteins in Heart and Skeletal Muscle Mitochondria from Trained and Untrained Mice

Contact Info

Product

Resources

About