Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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 number of recently described inherited disorders interfere with the oxidation of fatty acids. In these disorders at least three different metabolic steps may be affected: (1) transport of long chain fatty acids into the mitochondria as in carnitine deficiency and carnitine palmitoyl transferase deficiency (CPT); (2) multiple acyl CoA dehydrogenase deficiency or glutaric aciduria type II (GAII) due presumably to a defective common electron transfering flavoprotein or iron sulfur flavoprotein; (3) specific long or medium chain fatty acyl CoA dehydrogenase deficiency as in inherited dicarboxylic aciduria. In order to develop a system for the detection and the study of the consequences of defects such as these on the oxidation of fatty acids, we investigated the metabolism of oleate (18 carbons), octanoate (eight carbons) and butyrate (four carbons) in intact cultured fibroblasts from patients with CPT deficiency, GAII, and dicarboxylic aciduria. In CPT deficient cells there was a markedly deficient ability to oxidize [1-14C] and [U-14C] oleate (19 and 5% of normal, respectively), whereas oxidations of [1-14C] octanoate and [1,4-14C] succinate were significantly increased (150 and 222%, respectively), and [1-14C] butyrate oxidation was normal. GAII cells displayed a nearly complete defect in the oxidation of [1-14C] and [U-14C] oleate (8 and 1%, respectively), as well as of [1-14C] octanoate and [1-14C] butyrate (8 and 5% of normal, respectively). The oxidation of [1,4-14C] succinate by GAII cells was normal. Cells from a patient with dicarboxylic aciduria showed a significant reduction in [14CO2] production from [U-14C] oleate (57%) and [1-14C] octanoate (31%) and a normal oxidation of [1-14C] oleate, [1-14C] butyrate, and [1,4-14C] succinate. These observations are consistent with available information on the normal metabolism of fatty acids in liver and muscle and also with the hypothesis about the molecular localization of the defects in GAII and inherited dicarboxylic aciduria. They demonstrate that intact cultured skin fibroblasts represent a reliable and convenient model for the investigation of fatty acid oxidation in man. Many aspects of the human acyl CoA dehydrogenases and their physiologic functions remain unknown, among them the problem of their acyl chain length specificity. Studies in cultured fibroblasts from patients with presumed mutations affecting the metabolism of fatty acids provide a means for the elucidation of these defects and at the same time give information on normal metabolic functions. It appears likely that a number of previously unrecognized defects in this area of metabolism remain to be found. The availability of a model system for their study in cultured fibroblasts should facilitate their discovery.
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PMID:Oxidation of fatty acids in cultured fibroblasts: a model system for the detection and study of defects in oxidation. 714 11

Pig kidney general acyl-CoA dehydrogenases forms the blue neutral radical on dithionite or photochemical reduction (Thorpe, C., Matthews, R. G., & Williams, C. H. (1979) Biochemistry 18, 331-337] in accord with its classification as a flavoprotein dehydrogenase. However, dithionite reduction of the enzyme in the presence of crotonyl coenzyme A (crotonyl-CoA) or octenoyl-CoA generates the red radical anion as the predominant species at pH 7.6. Crotonyl-CoA binds preferentially to the red radical form, depressing the apparent pK by at least 2.5 pH units to a value of 7.3. Butyryl-, octanoyl-, and palmitoyl-CoA induce very similar spectral changes to those induced by enoyl-CoA derivatives when added anaerobically to the blue semiquinone enzyme. In contrast, the competitive inhibitors acetoacetyl-CoA and heptadecyl-SCoA do not markedly perturb the spectrum of the neutral flavosemiquinone species. The stability of the enzyme radical complexes with either crotonyl- or octanoyl-CoA suggests that there is not effective intraflavin transfer of reducing equivalents between subunits. Perturbation of the spectrum of the one-electron-reduced enzyme by ligands may complicate interpretation of the reaction enzyme by ligands may complicate interpretation of the reaction between substrate complexes of the general acyl-CoA dehydrogenase and electron-transferring flavoprotein.
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PMID:Stabilization of the red semiquinone form of pig kidney general acyl-CoA dehydrogenase by acyl coenzyme A derivatives. 729 60

It has previously been shown that the "partial" reaction between fatty acyl-CoA dehydrogenase and acyl-CoA substrate is pH-dependent (larger rate constants at basic pH) and shows a biphasic rate profile indicative of formation of an initial charge transfer complex between the C-2 anion of substrate and enzyme. The present investigation indicates that the complete reaction between acyl-CoA and electron transfer flavoprotein shows a pH profile dependent upon ionization of a single basic group with pKa = 7.7. these facts are consistent with electron transfer which occurs through an obligatory charge transfer complex between the C-2 anion of substrate and oxidized FAD at the enzyme active site. The anion of acetoacetyl-CoA forms a charge transfer complex with enzyme which serves as a model for the putative catalytically active complex mentioned above. Resonance Raman investigation of this acetoacetyl-CoA-enzyme complex indicates that the 1586 cm-1 band is coupled strongly to the charge transfer electronic transition. Since this vibrational band is associated with vC=N at N-5, C-4a of the flavin ring, we suggest that electron transfer takes place at this site.
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PMID:Mechanistic studies on fatty acyl-CoA dehydrogenase. 729 23

Three acyl-CoA dehydrogenases and electron transfer flavoprotein, which catalyze the initial step of mitochondrial fatty acid beta-oxidation, were purified from livers of rats fed a diet containing di(2-ethylhexyl)phthalate. Three acyl-CoA dehydrogenases, classified into short chain, general, and long chain acyl-CoA dehydrogenases on the basis of their substrate specificities, each consisted of four subunits of identical size: the molecular weights of the native enzymes were 169,000 for short chain acyl-CoA dehydrogenase, 182,000 for general acyl-CoA dehydrogenase, and 168,000 for long chain acyl-CoA dehydrogenase. Electron transfer flavoprotein with a molecular weight of 57,000 consisted of heterogeneous subunits with molecular weight of 33,500 and 25,100. The catalytic properties and molecular structures of rat liver acyl-CoA dehydrogenases were similar to those of the enzymes purified from other mammalian tissues such as pig heart, pig liver, and beef kidney. We could not obtain purified preparations of the three acyl-CoA dehydrogenases from livers of the control rats although the three dehydrogenases were completely separated from each other. The enzymes from the control and the di(2-ethylhexyl)phthalate-treated rats were compared and no differences were found in molecular sizes of the native enzymes and of their subunits, substrate specificities and immunochemical reactivities.
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PMID:Purification and properties of rat liver acyl-CoA dehydrogenases and electron transfer flavoprotein. 733 8

When amino acids were infused at a rate of 4 g/kg/day, an infant with hypoglycemia, metabolic acidemia and chronic regurgitation showed hypersarcosinemia and excreted abnormal amounts of sarcosine, isovalerylglycine, isobutyrylglycine, alpha-methylbutyrylglycine, and beta-hydroxyisovaleric, glutaric, alpha-hydroxyglutaric, methylsuccinic, and alpha-hydroxyisobutyric acids in urine. On all other occasions, when protein intake was lower and lipid intake higher, urine organic acids were dominated by methylsuccinic, ethylmalonic, and alpha-hydroxyglutaric acids, and hypersarcosinemia was absent. Autopsy showed severe fatty changes in liver, kidneys, and skeletal muscle. A previous female sibling had died with similar autopsy findings at 4 days of age. While activity of glutaryl-CoA dehydrogenase was completely deficient in liver and almost completely so in kidney, it was normal in cultured fibroblasts in the presence of flavin adenine dinucleotide (FAD) and only marginally low in its absence. Incorporation of D-(2-14C) riboflavin into flavin mononucleotides (FMN) and FAD by kidney tissue was normal. The authors conclude that this disorder is not due to generalized deficiency of glutaryl-CoA dehydrogenase or to a defect in FAD synthesis. The amino and organic acid abnormalities noted are most consistent with a defect in the flavoprotein which transfers electrons from the FAD of sarcosine and acyl-CoA dehydrogenases into the respiratory chain, although a defect in intercompartmental transfer of C4--5 acyl CoA esters across cell membranes is not excluded. The variability of the organic aciduria, which possibly reflects changes in protein and fat intake, suggests that a previous name for this disorder, i.e., glutaric aciduria type II, is inappropriate and should be replaced, perhaps by "multiple acyl-CoA dehydrogenase deficiency."
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PMID:Multiple acyl-CoA dehydrogenase deficiency (glutaric aciduria type II) with transient hypersarcosinemia and sarcosinuria; possible inherited deficiency of an electron transfer flavoprotein. 736 May 17

General acyl coenzyme A dehydrogenase from pig liver mitochondria, which was prepared as a complex with C8CoA and mixed with electron-transfer flavoprotein, rapidly reduces the electron-transfer flavoprotein to a 1-electron-reduced form (anionic semiquinone). A second electron is transferred more slowly to form the fully reduced electron-transfer flavoprotein. Transfer of the first electron is faster than turnover in the dichlorophenolindophenol reduction assay. These observations show that the acyl-CoA dehydrogenase-electron-transfer flavoprotein system utilizes this semiquinone catalytically. A concomitant appearance of semiquinone from the general acyl-CoA dehydrogenase could not be detected under similar conditions.
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PMID:Studies on electron transfer from general acyl-CoA dehydrogenase to electron transfer flavoprotein. 736 59

The flavoprotein pig kidney general acyl-CoA dehydrogenase contains a single catalytically essential methionine residue/FAD which reacts with iodoacetate at pH 6.6. S-Carboxymethylation of this residue generates an inactive enzyme derivative which retains FAD and the tetrameric structure of the native protein. The derivative binds actanoyl-CoA and palmityol-CoA with concomitant perturbation of the flavin chromophore, but the characterisitic spectrum of the reduced enzyme-enoyl-CoA complex is not observed. In addition, octanyol-CoA strongly protects the native enzyme against alkylation with iodoacetate. These results suggest that the methionine residue is within the active center of acyl-CoA dehydrogenase. Carboxymethylation of this residue may disrupt the precise orientation of the substrate required to achieve transfer of reducing equivalents to the flavin. Pig kidney general acyl-CoA dehydrogenase does not contain exposed catalytically essential cysteine residues.
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PMID:An essential methionine in pig kidney general acyl-CoA dehydrogenase. 745 27

A 62-year-old man was admitted to our hospital because of easy fatigability of the lower limbs during walking. The biopsied muscle specimen showed excessive lipid accumulation. The carnitine concentration in the muscle was at the lower level of the normal range. Organic acid urinalysis was consistent with the diagnosis of multiple acyl-CoA dehydrogenase deficiency or glutaric acidemia type II. In cultured lymphoblastoid cells from this patient there was impaired beta-oxidation, but the activities of acyl-CoA dehydrogenases were normal. Riboflavin therapy resulted in a dramatic improvement in both clinical and biochemical aspects. In this patient, the defect in coenzyme binding to electron transfer flavoprotein (ETF) or ETF-dehydrogenase was suspected. In the adult case of lipid storage myopathy, multiple acyl-CoA dehydrogenase deficiency should be suspected as one of its pathogenesis and riboflavin therapy should be considered.
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PMID:A riboflavin-responsive lipid storage myopathy due to multiple acyl-CoA dehydrogenase deficiency: an adult case. 785 27

We studied the effect of riboflavin treatment on the clinical status and on the activities of beta-oxidation and respiratory chain enzymes in a 69-year-old patient with late-onset myopathy. Before treatment, she was very weak and wasted in the limbs and trunk muscles; also, she could not walk or attend to daily activities. Marked lipid storage was present in the muscle biopsy. The activities of short-chain acyl coenzyme A (acyl-CoA) dehydrogenase (SCAD), medium-chain acyl-CoA dehydrogenase (MCAD), and long-chain acyl-CoA dehydrogenase (LCAD) in isolated muscle mitochondria were reduced to less than 10% of control values. This defect in fatty acid oxidation was associated with a marked deficiency of two flavin-dependent respiratory chain complexes: complex I activity was 20% and complex II activity was 25% of control values. By contrast, the activities of the nonflavin-dependent complex III and complex IV were normal. Western blot analysis of the patient's muscle mitochondrial extracts with antibodies raised against purified SCAD, MCAD, and the alpha- and beta-subunits of the electron transfer flavoprotein (ETF) showed absence of SCAD cross-reacting material (CRM), markedly decreased MCAD-CRM, and normal amounts of both alpha- and beta-ETF-CRM. After riboflavin treatment, the patient's clinical status dramatically improved and morphologic changes in muscle disappeared. SCAD activity increased to 55% of control values, whereas MCAD, LCAD, and complex I and complex II activities normalized. SCAD and MCAD immunoreactivity was restored to normal. On the basis of our experience and the data in the literature, we concluded that some lipid storage myopathies can show dramatic response to riboflavin.
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PMID:Late-onset riboflavin-responsive myopathy with combined multiple acyl coenzyme A dehydrogenase and respiratory chain deficiency. 796 76

Short chain (SCAD), medium chain (MCAD), and long chain acyl-CoA dehydrogenases (LCAD) catalyze the first step of fatty acid oxidation, while isovaleryl-CoA dehydrogenase (IVD) is involved in leucine oxidation. They are homologous flavoproteins belonging to the acyl-CoA dehydrogenase (ACD) family. Electron transfer flavoprotein (ETF) serves as an obligatory electron acceptor for these reactions. We demonstrated that the expression of SCAD, MCAD, and LCAD and the alpha-subunit of ETF (alpha-ETF) showed a similar developmental pattern, while that of IVD was distinctly different from others. The ontogenic pattern of each enzyme in the liver differed distinctly from that in the heart. The degree of glucagon-enhanced ACD expression in vivo and in vitro in both the liver and heart was especially high in fasted rats. Dexamethasone induced all ACD mRNAs in the heart. In contrast, it strongly suppressed mRNAs of all ACDs and alpha-ETF mRNA in the liver, except IVD mRNA. Dexamethasone induced IVD mRNA in both the liver and heart. Starvation strongly stimulated expression of all five genes in various tissues, with the highest in the heart, except the IVD gene which was down-regulated. The degree of induction by 3-day starvation differed in different age groups of rats. Feeding the rats a fat-free diet for 7 days caused a marked increase of IVD mRNA in the heart, whereas the high fat diet for the same period resulted in a severe decrease of the same degree, suggesting a protein-sparing mechanism. However, these manipulations of dietary fat content had little effect on the expression of other ACD genes.
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PMID:Developmental, nutritional, and hormonal regulation of tissue-specific expression of the genes encoding various acyl-CoA dehydrogenases and alpha-subunit of electron transfer flavoprotein in rat. 822 58


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