maleic-acid and malic-acid

Propionic acid (PA) predominantly accumulates in tissues and biological fluids of patients affected by propionic acidemia that may manifest chronic renal failure along development. High urinary excretion of maleic acid (MA) has also been described. Considering that the underlying mechanisms of renal dysfunction in this disorder are poorly known, the present work investigated the effects of PA and MA (1-5 mM) on mitochondrial functions and cellular viability in rat kidney and cultured human embryonic kidney (HEK-293) cells. Mitochondrial membrane potential (∆ψm), NAD(P)H content, swelling and ATP production were measured in rat kidney mitochondrial preparations supported by glutamate or glutamate plus malate, in the presence or absence of Ca

Topics: Adenosine Diphosphate; Adenosine Triphosphate; Animals; Calcium; Cyclosporine; Glutamic Acid; HEK293 Cells; Humans; Kidney; Kidney Failure, Chronic; Malates; Maleates; Membrane Potential, Mitochondrial; Mitochondria; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; NAD; Permeability; Propidium; Propionic Acidemia; Rats; Rats, Wistar

In contrast to the well-characterized and more common maleylpyruvate isomerization route of the gentisate pathway, the direct hydrolysis route occurs rarely and remains unsolved. In Pseudomonas alcaligenes NCIMB 9867, two gene clusters, xln and hbz, were previously proposed to be involved in gentisate catabolism, and HbzF was characterized as a maleylpyruvate hydrolase converting maleylpyruvate to maleate and pyruvate. However, the complete degradation pathway of gentisate through direct hydrolysis has not been characterized. In this study, we obtained from the NCIMB culture collection a Pseudomonas alcaligenes spontaneous mutant strain that lacked the xln cluster and designated the mutant strain SponMu. The hbz cluster in strain SponMu was resequenced, revealing the correct location of the stop codon for hbzI and identifying a new gene, hbzG. HbzIJ was demonstrated to be a maleate hydratase consisting of large and small subunits, stoichiometrically converting maleate to enantiomerically pure d-malate. HbzG is a glutathione-dependent maleylpyruvate isomerase, indicating the possible presence of two alternative pathways of maleylpyruvate catabolism. However, the hbzF-disrupted mutant could still grow on gentisate, while disruption of hbzG prevented this ability, indicating that the direct hydrolysis route was not a complete pathway in strain SponMu. Subsequently, a d-malate dehydrogenase gene was introduced into the hbzG-disrupted mutant, and the engineered strain was able to grow on gentisate via the direct hydrolysis route. This fills a gap in our understanding of the direct hydrolysis route of the gentisate pathway and provides an explanation for the high yield of d-malate from maleate by this d-malate dehydrogenase-deficient natural mutant.

Topics: Bacterial Proteins; Gentisates; Hydro-Lyases; Hydrolases; Hydrolysis; Malates; Maleates; Pseudomonas alcaligenes

The characterization of the metabolites accumulated in the grapes of specific cultivars grown in different climates is of particular importance for viticulturists and enologists. In the present study, the metabolite profiling of grapes from the cultivars, Alvarinho, Arinto and Padeiro de Basto, of two Portuguese Controlled Denomination of Origin (DOC) regions (Vinho Verde and Lisboa) was investigated by gas chromatography-coupled time-of-flight mass spectrometry (GC-TOF-MS) and an amino acid analyzer. Primary metabolites, including sugars, organic acids and amino acids, and some secondary metabolites were identified. Tartaric and malic acids and free amino acids accumulated more in grapes from vines of the DOC region of Vinho Verde than DOC Lisboa, but a principal component analysis (PCA) plot showed that besides the DOC region, the grape cultivar also accounted for the variance in the relative abundance of metabolites. Grapes from the cultivar, Alvarinho, were particularly rich in malic acid and tartaric acids in both DOC regions, but sucrose accumulated more in the DOC region of Vinho Verde.

Topics: Amino Acids; Chromatography, Gas; Citric Acid; Fructose; Fruit; Fumarates; Geography; Glucose; Malates; Maleates; Mass Spectrometry; Metabolome; Metabolomics; Portugal; Principal Component Analysis; Species Specificity; Succinic Acid; Sucrose; Tartrates; Vitis

An ion-exclusion chromatographic method for the simultaneous determination of organic acids in rice wine was developed. An IC-Pak Ion Exclusion column (300 mm x 7.8 mm, 7 microm) was used at 50 degrees C. The mobile phases were H2SO4 (phase A) and acetonitrile (phase B) (98:2, v/v) at a flow rate of 0.5 mL/min. The gradient elution program was as follows: 0-40 min, 0.01 mol/L H2SO4 to 0.02 mol/L H2SO4; 40-50 min, 0.01 mol/L H2SO4. The injection volume was 10 microL. The detection wavelength was set at 210 nm. The results showed that oxalic acid, maleic acid, citric acid, tartaric acid, malic acid, ascorbic acid, succinic acid, lactic, fumaric acid, acetic acid, propionic acid, isobutyric acid and butyric acid were completely separated and determined in 30 min. The linear correlation coefficients were above 0.999 7 in the range of 0.001- 1.000 g/L. Under the optimized conditions, the recoveries of organic acids in rice wine were in the range of 93.4% - 103.8% with the relative standard deviations (RSDs, n = 5) of 0.1% - 1.5%. This method is feasible, convenient, fast, accurate and applicable for the quantitative analysis of the organic acids in rice wine.

Topics: Acids; Chromatography, Gel; Fumarates; Malates; Maleates; Oryza; Oxalic Acid; Tartrates; Wine

Fumarate, a four-carbon trans dicarboxylic acid, is the allosteric activator of the human mitochondrial NAD(P)(+)-dependent malic enzyme (m-NAD(P)-ME). In this paper, we discuss the effects of the structural analogues of fumarate on human m-NAD(P)-ME. Succinate, a dicarboxylic acid with a carbon-carbon single bond, can also activate the enzyme, but the activating effect of succinate is less than that of fumarate. Succinamide, a diamide of succinate, cannot activate the enzyme and is a poor active-site inhibitor. The cis isomer of fumarate, maleic acid, significantly inhibits the ME activity, suggesting that the trans configuration of fumarate is crucial for operating the allosteric regulation of the enzyme. Other dicarboxylic acids, including glutaconic acid, malonic acid and alpha-ketoglutarate, cannot activate the enzyme and inversely inhibit enzyme activity. Our data suggest that these structural analogues are mainly active-site inhibitors, although they may enter the allosteric site to inhibit the enzyme. Furthermore, these data also suggest that the dicarboxylic acid must be in a trans conformation for allosteric activation of the enzyme.

Topics: Allosteric Regulation; Allosteric Site; Crystallography, X-Ray; Dicarboxylic Acids; Fumarates; Humans; Malate Dehydrogenase; Malates; Models, Molecular; Molecular Structure; Mutagenesis, Site-Directed; Protein Binding; Succinic Acid

A reliable method for the simultaneous determination of oxalic, fumaric, maleic, and succinic acids in tartaric and malic acids for pharmaceutical use by reversed-phase ion-suppression high performance liquid chromatography is presented. HPLC was achieved on a Nova-Pak C18 column by isocratic elution using water adjusted to pH 2.10-2.15 with perchloric acid, and detection was by UV adsorption at a wavelength of 210 nm. This method was found to be superior to previous liquid chromatography as well as other classical assay, and to be an attractive choice for the analysis of these compounds.

Topics: Chromatography, High Pressure Liquid; Dicarboxylic Acids; Drug Contamination; Evaluation Studies as Topic; Fumarates; Hydrogen-Ion Concentration; Malates; Maleates; Oxalic Acid; Perchlorates; Reproducibility of Results; Succinic Acid; Tartrates

Fumarate restores to flagella of cytoplasm-free, Che Y-containing envelopes of Escherichia coli and Salmonella typhimurium the ability to switch from one direction of rotation to another. To examine the specificity of this effect, we studied flagellar rotation of envelopes which contained, instead of fumarate, one of its analogues. Malate, maleate and succinate promoted switching, but to a lesser extent than fumarate. These observations were made both with wild-type envelopes and with envelopes of a mutant which lacks the enzymes succinate dehydrogenase and fumarase, indicating that the switching-promoting activity of the analogues was not caused by their conversion to fumarate. Aspartate and lactate did not promote switching. Using strains defective in specific enzymes of the tricarboxylic acid cycle and lacking the cytoplasmic chemotaxis proteins as well as some of the chemotaxis receptors, we demonstrated that, in intact bacteria, unlike the situation in envelopes, fumarate promoted clockwise rotation via its metabolites acetyl phosphate and acetyladenylate, but did not promote switching (presumably because of the presence of cytoplasmic fumarate). All of the results are consistent with the notion that fumarate acts as a switching factor, presumably by lowering the activation energy of switching. Thus fumarate and some of its metabolites may serve as a connection point between the bacterial metabolic state and chemotactic behaviour.

Topics: Aspartic Acid; Bacterial Proteins; Chemotaxis; Escherichia coli; Flagella; Fumarates; Lactic Acid; Malates; Maleates; Membrane Proteins; Methyl-Accepting Chemotaxis Proteins; Rotation; Salmonella typhimurium; Succinates; Succinic Acid

To produce D-malate from maleate by a microbial reaction, we screened a number of maleate-utilizing microorganisms for enzyme activity by an intact cell system. The strain which showed the best productivity among the 440 strains tested was identified taxonomically as Arthrobacter sp. strain MCI2612. The optical purity of the malate produced by this strain was 100% D type. The culture and reaction conditions for the production were studied for this strain. Addition of amino acids such as L-proline, L-histidine, and L-arginine to the culture medium promoted the formation of reaction activity as well as cell growth. Under optimum conditions, 87 g of D-malate per liter was produced in 20 h. The yield was 72 mol%.

Topics: Arthrobacter; Hydrogen-Ion Concentration; Malates; Maleates; Temperature

More than 300 microorganisms were screened for their ability to convert maleate into D-malate as a result of the action of maleate hydratase. Accumulation of fumarate during incubation of permeabilized cells with maleate was shown to be indicative of one of the two enzymes known to transform maleate. The ratio in which fumarate and malate accumulated could be used to estimate the enantiomeric composition of the malate formed. Many strains (n = 128) were found to be capable of converting maleate to D-malate with an enantiomeric purity of more than 97%. Pseudomonas pseudoalcaligenes NCIMB 9867 was selected for more detailed studies. Although this strain was not able to grow on maleate, permeabilized cells were able to degrade maleate to undetectable levels, with a concomitant formation of D-malate. The D-malate was formed with an enantiomeric purity of more than 99.97%.

Topics: Bacteria; Fungi; Isomerases; Malates; Maleates; Pseudomonas; Species Specificity; Stereoisomerism

Investigations based on computer simulated distributions of histamine in blood plasma were recently devoted to the assessment of the roles of cysteine, aspartic and glutamic acids as possible adjuvants of zinc to favour histamine tissue diffusion through mixed-ligand coordination. Since all tissues contain at least one of the two enzymes required for the catabolism of histamine, any increase of its tissue diffusion is expected to result in an acceleration of its degradation, which may be of interest for the treatment of anaphylactic disorders. As an extension of these studies, the present paper first reports (i) an experimental investigation of the tendency of four dicarboxylic acids, namely malate, malonate, tartrate and maleate, to mixed-ligand coordination with zinc and histamine, (ii) computer-based potential effects to be expected from the association of these agents to zinc with respect to histamine tissue diffusion. Cell culture studies were then used to test simulation expectations. Two series of experiments involving successively human lymphocytes and a lymphoblastoid cell line (8866) have been carried out, which led to the following conclusions: (i) the hypothesis formerly put forward that cysteine could favour histamine tissue diffusion through mixed-ligand coordination with zinc has been validated on the two cell models, (ii) the formerly established suppressive role of histamine versus lymphocyte proliferation has clearly been confirmed, (iii) moreover, this suppressive effect has been shown to occur correlatively to histamine uptake by these cells, (iv) the four dicarboxylic acids, more especially tartric acid, proved effective as catalysts of the two above processes. Possible biomedical applications of these results are discussed.

Topics: Cell Line; Cysteine; Diffusion; Histamine; Humans; Lymphocyte Activation; Lymphocytes; Malates; Maleates; Malonates; Tartrates; Zinc

Topics: Kidney; Malates; Maleates; Oxidation-Reduction