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Query: EC:1.3.1.8 (
acyl-CoA dehydrogenase
)
785
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
NADPH-Dependent enoyl-
CoA
reductase [
EC 1.3.1.8
] was purified to homogeneity, for the first time, from the crude extract of Mycobacterium smegmatis. The molecular weight of this enzyme was estimated to be around 32,000 using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified enzyme reduced 2-trans-hexadecenoyl-
CoA
(Km value, 100 microM) and -eicosenoyl-
CoA
(Km value, 83 microM) almost equally well in the presence of NADPH as a sole electron donor. The Km value for NADPH was 34.5 microM. When NADP3H was incubated with 2-eicosenoyl-
CoA
and the purified enzyme, the sole tritiated product was arachidate. This enzyme was almost inert to enoyl-CoAs with chains less than 12 carbon atoms long. The purified enzyme still retained FMN, which was detectable by acid ammonium sulfate and was essential for full activity of the enzyme. The enzyme was sensitive to SH-reagents such as N-ethylmaleimide and monoiodoacetamide but was not sensitive to isonicotinamide hydrazide. Anti-NADPH-dependent-enoyl-
CoA
-reductase rabbit serum was found to inhibit the activities of both the reductase and the malonyl-CoA dependent fatty acid elongation system, supporting the involvement of the reductase in this elongation system.
...
PMID:Purification of NADPH-dependent enoyl-CoA reductase involved in the malonyl-CoA dependent fatty acid elongation system of Mycobacterium smegmatis. 650 Dec 66
Three straight chain acyl-
CoA
dehydrogenases were purified to apparent homogeneity from bovine liver using 40-70% (NH4)2SO4 precipitation, gel filtration, DEAE-cellulose column chromatography, and preparative electrophoresis. Separation of the acyl-
CoA
dehydrogenases by these procedures has been efficiently monitored by two newly developed analytical methods: (i) native staining of acyl-
CoA
dehydrogenases following separation by electrophoresis in polyacrylamide gels and (ii) determination of general
acyl-CoA dehydrogenase
by means of a specific substrate, 4-cis-decenoyl-
CoA
. The three acyl-
CoA
dehydrogenases were classified into short chain, general, and long chain acyl-
CoA
dehydrogenases on the basis of their chain length specificities according to the nomenclature proposed by Hall and Kamin (Hall, C. L., and Kamin, H. (1975) J. Biol. Chem. 250, 3470-3486). The enzymes gave single protein bands in polyacrylamide gel electrophoresis under denaturing and nondenaturing conditions, and their subunit and native molecular weights were estimated to be 40,300 and 188,000 for short chain acyl-CoA dehydrogenase, 43,300 and 205,000 for general
acyl-CoA dehydrogenase
, and 45,200 and 172,000 for long chain acyl-CoA dehydrogenase. Long chain and general acyl-
CoA
dehydrogenases markedly differed in their substrate specificities toward unsaturated acyl-
CoA
esters with a double bond at position 4. The former oxidized 4-cis-decenoyl-
CoA
at a rate of only 2.7% of that obtained with decanoyl-
CoA
as substrate, while for the latter enzyme 4-cis-decenoyl-
CoA
was even a slightly better substrate than decanoyl-
CoA
. 2-trans,4-cis-Decenoyl-CoA was identified as the product of this reaction.
...
PMID:Purification and properties of acyl coenzyme A dehydrogenases from bovine liver. Formation of 2-trans,4-cis-decadienoyl coenzyme A. 654 82
Three children in two families presented in early childhood with episodes of illness associated with fasting which resembled Reye's syndrome: coma, hypoglycemia, hyperammonemia, and fatty liver. One child died with cerebral edema during an episode. Clinical studies revealed an absence of ketosis on fasting (plasma beta-hydroxybutyrate less than 0.4 mmole/liter) despite elevated levels of free fatty acids (2.6-4.2 mmole/liter) which suggested that hepatic fatty acid oxidation was impaired. Urinary dicarboxylic acids were elevated during illness or fasting. Total carnitine levels were low in plasma (18-25 mumole/liter), liver (200-500 nmole/g), and muscle (500-800 nmole/g); however, treatment with L-carnitine failed to correct the defect in ketogenesis. Studies on ketone production from fatty acid substrates by liver tissue in vitro showed normal rates from short-chain fatty acids, but very low rates from all medium and long-chain fatty acid substrates. These results suggested that the defect was in the mid-portion of the intramitochondrial beta-oxidation pathway at the medium-chain acyl-CoA dehydrogenase step. A new assay for the electron transfer flavoprotein-linked acyl-
CoA
dehydrogenases was used to test this hypothesis. This assay follows the decrease in electron transfer flavoprotein fluorescence as it is reduced by acyl-
CoA
-
acyl-CoA dehydrogenase
complex. Results with octanoyl-CoA as substrate indicated that patients had less than 2.5% normal activity of medium-chain acyl-CoA dehydrogenase. The activities of short-chain and isovaleryl acyl-
CoA
dehydrogenases were normal; the activity of long-chain acyl-CoA dehydrogenase was one-third normal. These results define a previously unrecognized inherited metabolic disorder of fatty acid oxidation due to deficiency of medium-chain acyl-CoA dehydrogenase.
...
PMID:Medium-chain acyl-CoA dehydrogenase deficiency in children with non-ketotic hypoglycemia and low carnitine levels. 664 97
The stereochemistry of the four partial reactions catalyzed by chicken liver fatty acid synthase that lead to the synthesis of palmitic acid has been determined. The reduction of acetoacetyl-CoA to 3-hydroxybutyryl-CoA by NADPH proceeds with the transfer of the pro-4S hydrogen of NADPH to form D-3-hydroxybutyryl-CoA. During the subsequent dehydration of D-3-hydroxybutyryl-CoA the pro-2S hydrogen and the 3-hydroxyl group are removed in a syn elimination to form crotonyl-
CoA
. Crotonyl-CoA is reduced to butyryl-CoA by NADPH, with the transfer of the pro-4R hydrogen of NADPH to the pro-3R position in butyryl-CoA and the transfer of a solvent hydrogen to the pro-2S position. The occurrence of the syn dehydration, when combined with the results of a previous study [ Sedgwick , B., & Cornforth , J. W. (1977) Eur. J. Biochem. 75, 465-479], implies that the condensation of the enzyme-bound malonyl moiety with the enzyme-bound saturated fatty acid to form a 3-keto intermediate proceeds with inversion at C-2 of the malonyl. The stereochemistry of the hydration was derived from an analysis of the spin-spin coupling constant of 3-hydroxy[2-2H]butyric acid benzylamides obtained from 3-hydroxy[2-2H]butyryl-CoA synthesized by fatty acid synthase. The elucidation of the stereochemistry of the reduction of crotonyl-
CoA
relied on the previously established stereochemistry of pork liver
acyl-CoA dehydrogenase
. The source of all 28 prochiral hydrogens of the palmitic acid synthesized by chicken liver fatty acid synthase was inferred from the results of this work.
...
PMID:Stereochemistry of the reactions catalyzed by chicken liver fatty acid synthase. 672 37
1. Dye-ligand chromatography using immobilized Cibacron blue F3GA (blue Sepharose CL-6B) and Procion red HE3B (Matrex gel red A) as matrices and general ligand chromatography employing immobilized 2',5'-ADP (2',5'-ADP-Sepharose 4B) and immobilized 3',5'-ADP (3',5'-ADP-Agarose) were employed for purification of NADPH-dependent
2-enoyl-CoA reductase
and 2,4-dienoyl-CoA reductase from bovine liver (formerly called 4-enoyl-CoA reductase [Kunau, W. H. and Dommes, P. (1978) Eur. J. Biochem. 91, 533-544], as well as 2,4-dienoyl-CoA reductase from Escherichia coli. 2. The NADPH-dependent
2-enoyl-CoA reductase
from bovine liver mitochondria was separated from 2,4-dienoyl-CoA reductase by dye-ligand chromatography (Matrex gel red A/KCl gradient) as well as by general ligand affinity chromatography (2',5'-ADP-Sepharose 4B/NADP gradient). The enzyme was obtained in a highly purified form. 3. The NADPH-dependent 2,4-dienoyl-CoA reductase from bovine liver mitochondria was purified to homogeneity using blue Sepharose CL-6B, Matrex gel red A, and 2',5'-ADP-Sepharose 4B chromatography. 4. The bacterial 2,4-dienoyl-CoA reductase was completely purified by ion-exchange chromatography on DEAE-cellulose followed by a single affinity chromatography step employing 2',5'-ADP-Sepharose 4B and biospecific elution from the column with a substrate, trans,trans-2,4-decadienoyl-
CoA
. 5. The application of dye-ligand and general ligand affinity chromatography for purification of NADPH-dependent 2,4-dienoyl-
CoA
reductases taking part in the beta-oxidation of unsaturated fatty acids is discussed. It is concluded that making use of coenzyme specificity for binding and substrate specificity for elution is essential for obtaining homogeneous enzyme preparations.
...
PMID:Purification by affinity chromatography of 2,4-dienoyl-CoA reductases from bovine liver and Escherichia coli. 674 95
2-Methyl-branched chain
acyl-CoA dehydrogenase
was purified to homogeneity from rat liver mitochondria. The native molecular weight of the enzyme was estimated to be 170,000 by gel filtration. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis both with and without 2-mercaptoethanol, the enzyme showed a single protein band with Mr = 41,500, suggesting that this enzyme is composed of four subunits of equal size. Its isoelectric point was 5.50 +/- 0.2, and A1%280 nm was 12.5. This enzyme contained protein-bound FAD. The purified enzyme dehydrogenated S-2-methylbutyryl-
CoA
and isobutyryl-
CoA
with equal activity. The activities with each of these compounds were co-purified throughout the entire purification procedure. This enzyme also dehydrogenated R-2-methylbutyryl-
CoA
, but the specific activity was considerably lower (22%) than that for the S-enantiomer. The enzyme did not dehydrogenate other acyl-CoAs, including isovaleryl-
CoA
, propionyl-
CoA
, butyryl-CoA, octanoyl-CoA, and palmitoyl-CoA, at any significant rate. Apparent Km and Vmax values for S-2-methylbutyryl-
CoA
were 20 microM and 2.2 mumol min-1 mg-1, respectively, while those for isobutyryl-
CoA
were 89 microM and 2.0 mumol min-1 mg-1 using phenazine methosulfate as an artificial electron acceptor. The enzyme was also active with electron transfer flavoprotein. Tiglyl-
CoA
and methacrylyl-
CoA
were identified as the reaction products from S-2-methylbutyryl-
CoA
and isobutyryl-
CoA
, respectively. 2-Ethylacrylyl-
CoA
was produced from R-2-methylbutyryl-
CoA
. Tiglyl-
CoA
competitively inhibited the activity with both S-2-methylbutyryl-
CoA
and isobutyryl-
CoA
with a similar Ki. The enzyme activity was also severely inhibited by several organic sulfhydryl reagents such as N-ethylmaleimide, p-hydroxymercuribenzoate, and methyl mercury iodide. The pattern and degree of inhibition were essentially identical for both substrates. The purified 2-methyl-branched chain
acyl-CoA dehydrogenase
was immunologically distinct from isovaleryl-
CoA
-, short chain acyl-
CoA
-, medium chain acyl-
CoA
-, or long chain acyl-CoA dehydrogenase.
...
PMID:Purification and characterization of 2-methyl-branched chain acyl coenzyme A dehydrogenase, an enzyme involved in the isoleucine and valine metabolism, from rat liver mitochondria. 687 97
Unadapted rats and other animal species have a limited capacity to metabolize monounsaturated fatty acids with 22 carbons (22:1). Excess amounts in the diet of fats containing these fatty acids cause a transient accumulation (lipidosis) of triacylglycerol in the heart and other tissues but not in the liver, which seems to export the 22:1 fatty acids as very low density lipoproteins to the blood plasma. The acute lipidosis most probably is explained by a slow oxidation of 22:1 acyl-
CoA
by the mitochondrial
acyl-CoA dehydrogenase
combined with an inhibitory effect of this
CoA
ester on the oxidation of acyl-
CoA
esters of a more "normal" chain length. Other fatty acid metabolizing enzymes also show slow reaction rates with the 22:1 fatty acids. Upon continued feeding of diets with 22:1 fatty acids, an adaptation takes place and the lipidosis disappears. This adaptation coincides with the development of an increased capacity to chain-shorten the 22:1 fatty acids, especially in the liver, but also in the heart. The chain-shortening seems to be due to a partial beta-oxidation of the 22:1 fatty acids by the peroxisomal beta-oxidation enzyme system which shows an increased activity in adapted rats. In such rats, less 22:1 fatty acids circulate in the plasma very low density lipoproteins than in unadapted rats. The drug clofibrate (ethyl-p-chlorophenoxyisobutyrate) which induces increased activity of the peroxisomal beta-oxidation enzymes, provides partial protection against the lipidosis in unadapted animals. Hydrogenated fish oil (containing different 22:1 isomers and many fatty acids with trans double bonds) is more efficient as an inducer of the chain-shortening of erucic acid in the liver than is rapeseed oil, which contains only one 22:1 fatty acid isomer and no fatty acids with trans double bonds. The hydrogenated fish oil causes less lipidosis than does rapeseed oil when diets containing the same amount of 22:1 fatty acids are fed. It is suggested that
CoA
esters that are poorly oxidized by the mitochondria (e.g., esters of erucic acid, of some fatty acids with trans double bonds, and of clofibric acid) may trigger the adaptation process.-Bremer, J., and K. R. Norum. Metabolism of very long-chain monounsaturated fatty acids (22:1) and the adaptation to their presence in the diet.
...
PMID:Metabolism of very long-chain monounsaturated fatty acids (22:1) and the adaptation to their presence in the diet. 704 78
Yellow butyryl-CoA dehydrogenase and general
acyl-CoA dehydrogenase
are "greened" by a mixture of coenzyme A plus elemental sulfur. The resultant stable complex contains an identical ligand with that present in native green butyryl-CoA dehydrogenase and has the same broad absorption band centered at 710 nm. Evidence is presented that the greening ligand is a
CoA
persulfide, possibly a mimic of the substrate carbanion thought to be generated early in the normal catalytic cycle. Variation in the position of the long wavelength band on replacement of FAD by a series of analogs of differing oxidation-reduction potential is consistent with a charge-transfer complex between a persulfide as the donor and oxidized flavin as the acceptor. The possible physiological and metabolic significance is discussed.
...
PMID:Evidence that the greening ligand in native butyryl-CoA dehydrogenase is a CoA persulfide. 706 37
Rats were maintained on fat-free high carbohydrate diets either with or without orotic acid (1%, w/w), pantethine (1%, w/w), adenine (0.25%, w/w), and/or p-chlorophenoxyisobutyrate (0.25%, w/w). Oxidation of fatty acid by liver mitochondria was inhibited to less than half that of the control after administration of orotic acid. Activities of acyl-
CoA
dehydrogenases were markedly decreased by orotic acid administration, but the following enzyme activities were not, or only slightly decreased: acyl-CoA synthetase, carnitine acyltransferases, enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase and 3-ketoacyl-CoA thiolase. Simultaneous addition of pantethine in the orotic acid-containing diet prevented induction of fatty liver. It also prevented decreases in fatty acid oxidation capacity and
acyl-CoA dehydrogenase
activity. Introduction of adenine or p-chlorophenoxyisobutyrate, which reverse orotic acid-induced fatty liver, reversed oxidation and
acyl-CoA dehydrogenase
activities to control levels. The oxidation capacity of the peroxisomal system remained unchanged after administration of orotic acid.
...
PMID:Reduction of beta-oxidation capacity of rat liver mitochondria by feeding orotic acid. 710 78
Weanling rats were fed a riboflavin-deficient diet. The mitochondrial fatty acid oxidation in liver was depressed in riboflavin deficiency but restored after supplementation of riboflavin. Among the enzymes involved in this system, only the
acyl-CoA dehydrogenase
(EC 1.3.99.2 and 1.3.99.3) activities varied with the change in fatty acid oxidation. An accumulation of the apoforms of acyl-
CoA
dehydrogenases was found in riboflavin deficiency. The levels of electron transfer flavoprotein and other enzymes involved in the beta-oxidation system remained unchanged. The peroxisomal fatty acid oxidation and levels of individual enzymes of this system remained constant. No accumulation of the apoform of acyl-CoA oxidase was observed under simple, riboflavin-deficient conditions. However, accumulation of a large amount of apo-acyl-CoA oxidase was observed when the peroxisomal system was induced by administration of a peroxisome proliferator, di(2-ethylhexyl)phthalate, under riboflavin-deficient conditions.
...
PMID:Riboflavin deficiency and beta-oxidation systems in rat liver. 714 48
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