Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.3.99.3 (acyl-CoA dehydrogenase)
 1,425 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A novel approach to the analysis of acylcarnitines has been developed. It involves a direct esterification using propyl chloroformate in aqueous propanol followed by ion-pair extraction with potassium iodide into chloroform and subsequent on-column N-demethylation of the resulting acylcarnitine propyl ester iodides. The products, acyl N-demethylcarnitine propyl esters, are volatile and are easily analyzed by gas chromatography-chemical ionization mass spectrometry. For medium-chain-length (C4-C12) acylcarnitine standards, detection limits are demonstrated to be well below 1 ng starting material using selected ion monitoring. Well-separated gas chromatographic peaks and structure-specific mass spectra are obtained with samples of synthetic and biological origin. Seven acylcarnitines have been characterized in the urine of a patient suffering from medium-chain acyl-CoA dehydrogenase deficiency.
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PMID:Analysis of acylcarnitines as their N-demethylated ester derivatives by gas chromatography-chemical ionization mass spectrometry. 180 68

The free two-electron-reduced form of medium-chain acyl-CoA dehydrogenase is reoxidized by 120 microM molecular oxygen (50 mM phosphate buffer, pH 7.6, 2 degrees C) with a half-time of approximately 7 s. Reoxidation yields hydrogen peroxide as a major product with only traces of the superoxide anion. In contrast, enzyme reduced with octanoyl-CoA is extremely slowly reoxidized oxygen, and so a series of 14 different substrate analogues have been tested to assess the structural factors responsible for this effect. Complexes with redox-inactive ligands such as 3-thia- and 2-azaoctanoyl-CoA lead to an approximately 3000-fold slowing of the rate of reoxidation of the free dihydroflavin form of the enzyme. Comparable ligands lacking the thioester carbonyl function are much less effective with rates some 1.3-4-fold slower than the free enzyme. The strong suppression of oxygen reactivity observed with certain ligands is probably not simply a steric effect but may reflect desolvation of the active site and consequent destabilization of the superoxide anion intermediate formed during reoxidation of the flavin. The profound differences in oxygen reactivity between acyl-CoA dehydrogenase and acyl-CoA oxidase and the unusual stability of certain flavoprotein semiquinones in air are discussed in terms of these thermodynamic and kinetic arguments.
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PMID:Reactivity of medium-chain acyl-CoA dehydrogenase toward molecular oxygen. 186 64

Dicarboxylic aciduria occurs during increased mobilization or inhibited beta-oxidation of fatty acids. In these conditions, a number of 3-hydroxydicarboxylic acids are excreted in the urine. These 3-hydroxydicarboxylic acids include 3-hydroxyadipic (3OHDC6), 3-hydroxyoctanedioic (3OHDC8), 3-hydroxydecanedioic (3OHDC10), 3-hydroxydodecanedioic (3OHDC12), and a number of unsaturated homologues. The metabolic origin of these 3-hydroxydicarboxylic acids is from the omega-oxidation of 3-hydroxy fatty acids. Subsequent beta-oxidation of the dicarboxylates yields lower-chain 3-hydroxydicarboxylic acids. A new defect in fatty acid oxidation characterized by increased urinary ratios of 3OHDC6, 3OHDC12, and unsaturated 3OHDC14s relative to 3OHDC10 is described. This pattern is consistent with a defect in long-chain 3-hydroxyacyl-CoA dehydrogenase (LHAD), which was confirmed by enzyme assay in fibroblasts. In contrast, patients with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency had lower ratios of 3OHDC6 and 3OHDC8 to 3OHDC10, consistent with a decreased activity of MCAD. Nonketotic dicarboxylic aciduria, other than MCAD and LHAD deficiencies, is shown to have a normal 3-hydroxydicarboxylic acid profile when compared with fasting normal controls. Since increased excretion of 3-hydroxydicarboxylic acids was observed in all patients with dicarboxylic aciduria, an increased excretion of these compounds is not an adequate criterion to suspect a defect in 3-hydroxyacyl-CoA dehydrogenases. The analysis of the metabolite ratios (3OHDC6 and 3OHDC12 relative to 3OHDC10) is a more useful indicator for defects in LHAD.
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PMID:Urinary 3-hydroxydicarboxylic acids in pathophysiology of metabolic disorders with dicarboxylic aciduria. 187 Apr 21

To study the structure-activity relationship between pentanoic acid analogues and the inhibition of fatty acid oxidation, a number of 4-pentenoic and methylenecyclopropaneacetic acid derivatives were prepared. All compounds inhibited palmitoylcarnitine oxidation in rat liver mitochondria, with 50% inhibition occurring at a concentration between 6 and 100 microM. However, only methylenecyclopropaneacetic acid (MCPA) and spiropentaneacetic acid (SPA) showed in vivo inhibitory activity in rats as indicated by the occurrence of dicarboxylic aciduria. Rats treated with SPA excreted metabolites derived only from fatty acid oxidation whereas MCPA-treated rats also excreted metabolites derived from branch-chained amino acid and lysine metabolism. SPA is a specific inhibitor of fatty acid oxidation without affecting amino acid metabolism. The site of inhibition is medium-chain acyl-CoA dehydrogenase (MCAD). In contrast, MCPA inhibited both MCAD and short-chain acyl-CoA dehydrogenase with a stronger inhibition toward the latter. The inhibition of fatty acid oxidation by both inhibitors was partially reversible by glycine or l-carnitine. Since SPA does not form a ring-opened nucleophile such as that proposed for MCPA in the inhibition of FAD prosthetic group in acyl-CoA dehydrogenases, we propose that the irreversible inhibition by SPA occurs by a tight complex without forming a covalent bond to the isoalloxazine ring in FAD.
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PMID:Spiropentaneacetic acid as a specific inhibitor of medium-chain acyl-CoA dehydrogenase. 193 95

Long-chain acyl-CoA dehydrogenase (LCAD) deficiency is a disorder of mitochondrial fatty acid oxidation that is characterized by hypoglycemia, muscle weakness, and hepato- and cardiomegaly. To characterize variant LCAD, we first carried out preliminary experiments using pure enzyme preparations. Despite the significant sequence similarity of LCAD to medium-chain acyl-CoA dehydrogenase, the antibody raised against rat LCAD was monospecific for human and rat LCAD and did not cross-react with either human or rat medium-chain acyl-CoA dehydrogenase. Immunoblot analysis of variant LCAD in cultured fibroblasts from nine patients with LCAD deficiency revealed a single LCAD band in all nine LCAD-deficient cell lines. Each variant LCAD was comparable in molecular size and quantity to normal LCAD, suggesting that the LCAD mutation in each of these cell lines is likely to be a point mutation that produces a stable variant LCAD. The uniform nature of variant LCAD suggests that only a single, or at most a few, prevalent point mutations may be found in the majority of LCAD-deficient patients. If this is the case, it should be possible to devise a molecular diagnostic method for LCAD deficiency.
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PMID:Immunochemical characterization of variant long-chain acyl-CoA dehydrogenase in cultured fibroblasts from nine patients with long-chain acyl-CoA dehydrogenase deficiency. 194 57

Screening urine for inherited and acquired organic acidurias in newborns has the potential of preventing severe disease, mental retardation, and death. A method for screening dried urine filter paper samples for acidic markers of at least 20 different metabolic conditions has been developed. These conditions include, among others, maple syrup urine disease; methylmalonic, propionic, isovaleric, glutaric, and hydroxymethylglutaric acidurias; methylcrotonylglycinuria; medium-chain acyl-CoA dehydrogenase deficiency; inherited vitamin responsive disorders B12, biotin, B2), and acquired deficiencies of these vitamins. The preparation of the urine extract is identical to the method we use to screen infants for neuroblastoma. Screening is based on a highly sensitive and specific determination of eight organic acid markers by an automated computerized gas chromatography mass spectrometry system using selected ion monitoring. The markers used for screening are methylmalonic acid, 2-hydroxyisocaproic acid, glutaric acid, propionylglycine, isovalerylglycine, 3-methylcrotonylglycine, hexanoylglycine, and 3-phenylpropionylglycine. The extraction efficiencies of these acids from dried filter paper were similar to extraction from water, ranging from about 40% to 80%, except for propionylglycine which showed a low extraction efficiency of 11-13%. The stability of these acids on filter paper exposed to room air and temperature over a period of 15 d was adequate for the use of this collection method for organic aciduria screening. Normal levels, adjusted to urinary creatinine, were established for these acids in 519 urine filter paper samples obtained from 3-wk-old newborns. This screening method was tested on samples obtained from 12 patients with known organic acidurias including stored urine filter paper collected at 3-wk of age from two infants later found to have organic acidurias.
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PMID:Screening newborns for multiple organic acidurias in dried filter paper urine samples: method development. 195 13

The gene for medium-chain acyl-CoA dehydrogenase (gene symbol ACADM; enzyme symbol MCAD) has been characterized for restriction fragment length polymorphisms (RFLPs) and mapped by linkage analysis to 4.2 cM from D1S2 and 11.7 cM from PGM1. The three RFLP systems described in detail show significant linkage disequilibrium but define four haplotypes with a PIC of 0.58. This makes ACADM informative for linkage mapping and for clinical genetic studies. By linkage studies, the orientation of these three loci relative to the centromere places ACADM most proximal. This is in direct conflict with the regional assignments of ACADM to 1p31 by in situ hybridization and of PGM1 to 1p22.1 by somatic cell studies. We suggest that this somatic cell localization of PGM1 may be incorrect.
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PMID:The locus for the medium-chain acyl-CoA dehydrogenase gene on chromosome 1 is highly polymorphic. 196 47

Inherited defects in fatty acid oxidation, which have been described and diagnosed with increasing frequency in the last decade, are most commonly attributed to a deficiency in the activity of medium-chain acyl-CoA dehydrogenase. Few cases of the related enzyme defect of long-chain acyl-CoA dehydrogenase activity have been reported. An infant with documented long-chain acyl-CoA dehydrogenase deficiency is described with a detailed metabolic profile, long-term clinical follow-up, and response to treatment. This patient is compared with the seven previously published cases of this disorder in order to stress the unique features of the initial presentation, more subtle late manifestations of the disease, and clinical and biochemical differentiation from the more common medium-chain acyl-CoA dehydrogenase deficiency. This report stresses the enlarging spectrum of the clinical presentation and natural history of this defect in fatty acid oxidation.
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PMID:Hypoglycemia, hypotonia, and cardiomyopathy: the evolving clinical picture of long-chain acyl-CoA dehydrogenase deficiency. 200 Feb 72

The production of tritiated water from [9,10-3H]myristic acid can be used as a screening assay for the detection of medium-chain acyl-CoA dehydrogenase deficiency, multiple acyl-CoA dehydrogenation defects (glutaric aciduria type 2 and ethylmalonic-adipic aciduria types), and some types of hydroxydicarboxylic aciduria. Comparison with the release of tritiated water from [9,10-3H]palmitic acid may give an indication of the chain-length specificity of the metabolic defect. In a case of ethylmalonic-adipic aciduria such a prediction has been confirmed by examination of accumulated intermediates in the affected fibroblasts.
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PMID:A comparison of [9,10-3H]palmitic and [9,10-3H]myristic acids for the detection of defects of fatty acid oxidation in intact cultured fibroblasts. 210 49

We report a family in whom a fatal case of medium-chain acyl-CoA dehydrogenase (MCAD; EC 1.3.99.3) deficiency was diagnosed by enzymatic analysis of heart tissue that had been stored for five years. Three healthy siblings underwent subsequent investigation with the 3-phenylpropionic acid loading test. All siblings had been asymptomatic; however, one (age 2.5 years) excreted large amounts of 3-phenylpropionylglycine in response to the load and exhibited an organic aciduria consistent with the diagnosis of MCAD deficiency. The other two siblings did not demonstrate 3-phenylpropionylglycinuria after the loading test. This case underlines the importance of considering family history and using appropriate diagnostic tests in the recognition of hereditary metabolic disorders.
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PMID:Medium-chain acyl-CoA dehydrogenase deficiency: a useful diagnosis five years after death. 220 22


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