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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)
Five distinct acyl-CoA dehydrogenases are currently known. These are short, medium, long and 2-methyl-branched-chain acyl-CoA dehydrogenases, and isovaleryl-CoA dehydrogenase. We tested these five acyl-CoA dehydrogenases for their ability to dehydrogenate valproyl-CoA using pure enzyme preparations isolated from rat liver mitochondria. The activities of the pure human short-chain, medium-chain and isovaleryl enzymes purified from post-mortem livers, and a
long-chain acyl-CoA dehydrogenase
preparation partially purified from placental mitochondria, were also tested. Valproyl-CoA was dehydrogenated at a significant rate (0.167 mumol/min per mg protein) only by rat 2-methyl-branched-chain acyl-CoA dehydrogenase. Human 2-methyl-branched-chain acyl-CoA dehydrogenase has not been purified; therefore, it could not be tested. Since four other human acyl-CoA dehydrogenases did not dehydrogenate isobutyryl-CoA, 2-methylbutyryl-CoA (obligatory intermediates from
valine
and isoleucine, respectively) nor valproyl-CoA, it is reasonable to assume that valproyl-CoA is dehydrogenated by 2-methyl-branch-chain
acyl-CoA dehydrogenase
in man as well. We identified 2-propyl-2-pentenoyl-CoA as the reaction product from valproyl-CoA by mass spectral analysis of the acyl moiety. Valproyl-CoA, at 0.3 mM, moderately inhibited human acyl-CoA dehydrogenases with the exception of the long-chain enzyme. 5 mM free valproic acid inhibited the activities of various acyl-CoA dehydrogenases only very weakly.
...
PMID:The enzymatic basis for the metabolism and inhibitory effects of valproic acid: dehydrogenation of valproyl-CoA by 2-methyl-branched-chain acyl-CoA dehydrogenase. 211 56
Inactivation of five distinct acyl-CoA dehydrogenases by (methylenecyclopropyl)acetyl-CoA (MCPA-CoA), the toxic metabolite of hypoglycin from unripe ackee fruit, was investigated using purified enzyme preparations. Short-chain acyl-CoA (SCADH), medium-chain acyl-CoA (MCADH) and isovaleryl-CoA (IVDH) dehydrogenases were severely and irreversibly inactivated by MCPA-CoA, while 2-methyl-branched chain
acyl-CoA dehydrogenase
(2-meBCADH) was only slowly and mildly inactivated. Long-chain
acyl-CoA dehydrogenase
(LCADH) was not significantly inactivated, even after prolonged incubation with MCPA-CoA. Inactivation of SCADH, MCADH and IVDH was effectively prevented by the addition of substrate. This mode of inactivation by MCPA-CoA explains the urinary metabolite profile in hypoglycin treated-rats, which includes large amounts of metabolites from fatty acids and leucine, and relatively small amounts of those from
valine
and isoleucine. Spectrophotometric titration of SCADH and MCADH with MCPA-CoA, together with the protective effects of substrate, indicates that MCPA-CoA is acted upon by, and exerts in turn irreversible inactivation of, SCADH and MCADH, confirming that MCPA-CoA is a suicide inhibitor (Wenz et al. (1981) J. Biol. Chem. 256, 9809-9812). Spectrophotometric titration data of LCADH and MCPA-CoA is typical of non-reacting CoA ester.
...
PMID:Selective inactivation of various acyl-CoA dehydrogenases by (methylenecyclopropyl)acetyl-CoA. 233 85
A 2-year-old female was well until 12 months of age when she was found to be anemic and had dilated cardiomyopathy. Total plasma carnitine was 6 microM and acylcarnitine analysis while receiving carnitine supplement revealed an increase in the four-carbon species. Urine organic acids were normal. In vitro analysis of the mitochondrial pathways for beta oxidation, and leucine,
valine
, and isoleucine metabolism was performed in fibroblasts using stable isotope-labeled precursors to these pathways followed by acylcarnitine analysis by tandem mass spectrometry. 16-2H3-palmitate was metabolized normally down to the level of butyryl-CoA thus excluding SCAD deficiency. 13C6-leucine and 13C6-isoleucine were also metabolized normally. 13C5-
valine
incubation revealed a significant increase in 13C4-isobutyrylcarnitine without any incorporation into propionylcarnitine as is observed normally. These same precursors were also evaluated in fibroblasts with proven ETF-QO deficiency in which
acyl-CoA dehydrogenase
deficiencies in each of these pathways was clearly identified. These results indicate that in the human, there is an isobutyryl-CoA dehydrogenase which exists as a separate enzyme serving only the
valine
pathway in addition to the 2-methyl branched-chain dehydrogenase which serves both the
valine
and the isoleucine pathways in both rat and human.
...
PMID:Isolated isobutyryl-CoA dehydrogenase deficiency: an unrecognized defect in human valine metabolism. 988 13
The cloning, using a PCR approach, of genes from both Streptomyces coelicolor and Streptomyces avermitilis encoding an
acyl-CoA dehydrogenase
(AcdH), putatively involved in the catabolism of branched-chain amino acids, is reported. The deduced amino acid sequences of both genes have a high similarity to prokaryotic and eukaryotic short-chain acyl-CoA dehydrogenases. When the S. coelicolor and S. avermitilis
acyl-CoA dehydrogenase
genes (acdH) were expressed in Escherichia coli, each of the AcdH flavoproteins was able to oxidize the branched-chain acyl-CoA derivatives isobutyryl-CoA, isovaleryl-CoA and cyclohexylcarbonyl-CoA, as well as the short straight-chain acyl-CoAs n-butyryl-CoA and n-valeryl-CoA in vitro. NMR spectral data confirmed that the oxidized product of isobutyryl-CoA is methacrylyl-CoA, which is the expected product at the
acyl-CoA dehydrogenase
step in the catabolism of
valine
in streptomycetes. Disruption of the S. avermitilis acdH produced a mutant unable to grow on solid minimal medium containing
valine
, isoleucine or leucine as sole carbon sources. Feeding studies with 13C triple-labelled isobutyrate revealed a significant decrease in the incorporation of label into the methylmalonyl-CoA-derived positions of avermectin in the acdH mutant. In contrast the mutation did not affect incorporation into the malonyl-CoA-derived positions of avermectin. These results are consistent with the acdH gene encoding an
acyl-CoA dehydrogenase
with a broad substrate specificity that has a role in the catabolism of branched-chain amino acids in S. coelicolor and S. avermitilis.
...
PMID:Genes encoding acyl-CoA dehydrogenase (AcdH) homologues from Streptomyces coelicolor and Streptomyces avermitilis provide insights into the metabolism of small branched-chain fatty acids and macrolide antibiotic production. 1051 85
The acyl-CoA dehydrogenases (ACDs) are a family of related enzymes that catalyze the alpha,beta-dehydrogenation of acyl-CoA esters. Two homologues active in branched chain amino acid metabolism have previously been identified. We have used expression in Escherichia coli to produce a previously uncharacterized
ACD
-like sequence (ACAD8) and define its substrate specificity. Purified recombinant enzyme had a k(cat)/K(m) of 0.8, 0.23, and 0.04 (microM(-1)s(-1)) with isobutyryl-CoA, (S) 2-methylbutyryl-CoA, and n-propionyl-CoA, respectively, as substrates. Thus, this enzyme is an isobutyryl-CoA dehydrogenase. A single patient has previously been described whose fibroblasts exhibit a specific deficit in the oxidation of
valine
. Amplified ACAD8 cDNA made from patient fibroblast mRNA was homozygous for a single nucleotide change (905G>A) in the ACAD8 coding region compared to the sequence from control cells. This encodes an Arg302Gln substitution in the full-length protein (position 280 in the mature protein), a position predicted by molecular modeling to be important in subunit interactions. The mutant enzyme was stable but inactive when expressed in E. coli. It was also stable and appropriately targeted to mitochondria, but inactive when expressed in mammalian cells. These data confirm further the presence of a separated
ACD
in humans specific to
valine
catabolism (isobutyryl-CoA dehydrogenase, IBDH), along with the first enzymatic and molecular confirmation of a deficiency of this enzyme in a patient.
...
PMID:Identification of isobutyryl-CoA dehydrogenase and its deficiency in humans. 1235 32
The isobutyryl-CoA dehydrogenase (IBD) enzyme is involved in the degradation of
valine
. IBD deficiency was first reported in 1998 and subsequent genetic investigations identified
acyl-CoA dehydrogenase
(
ACAD
) 8, now IBD, as the gene responsible for IBD deficiency. Only three individuals homozygous or compound heterozygous for variations in the IBD gene have been reported. We present IBD deficiency in an additional four newborns with elevated C(4)-carnitine identified by tandem mass spectrometry (MS/MS) screening in Denmark and the United States. Three showed urinary excretions of isobutyryl-glycine, and in vitro probe analysis of fibroblasts from two newborns indicated enzymatic IBD defect. Molecular genetic analysis revealed seven new rare variations in the IBD gene (c.348C>A, c.400G>T, c.409G>A, c.455T>C, c.958G>A, c.1000C>T and c.1154G>A). Furthermore, sequence analysis of the short-chain acyl-CoA dehydrogenase (SCAD) gene revealed heterozygosity for the prevalent c.625G>A susceptibility variation in all newborns and in the first reported IBD patient. Functional studies in isolated mitochondria demonstrated that the IBD variations present in the Danish newborn (c.409G>A and c.958G>A) together with a previously published IBD variation (c.905G>A) disturbed protein folding and reduced the levels of correctly folded IBD tetramers. Accordingly, low/no IBD residual enzyme activity was detectable when the variant IBD proteins were overexpressed in Chang cells.
...
PMID:Variations in IBD (ACAD8) in children with elevated C4-carnitine detected by tandem mass spectrometry newborn screening. 1685 60
An
acyl-CoA dehydrogenase
has been identified as part of the mitochondrial beta-oxidation pathway in the ascomycete fungus Aspergillus nidulans. Disruption of the scdA gene prevented use of butyric acid (C(4)) and hexanoic acid (C(6)) as carbon sources and reduced cellular butyryl-CoA dehydrogenase activity by 7.5-fold. While the mutant strain exhibited wild-type levels of growth on erucic acid (C(22:1)) and oleic acid (C(18:1)), some reduction in growth was observed with myristic acid (C(14)). The DeltascdA mutation was found to be epistatic to a mutation downstream in the beta-oxidation pathway (disruption of enoyl-CoA hydratase). The DeltascdA mutant was also unable to use isoleucine or
valine
as a carbon source. Transcription of scdA was observed in the presence of either fatty acids or amino acids. When the mutant was grown in medium containing either isoleucine or
valine
, organic acid analysis of culture supernatants showed accumulation of 2-oxo acid intermediates of branched chain amino acid catabolism, suggesting feedback inhibition of the upstream branched-chain alpha-keto acid dehydrogenase.
...
PMID:A single acyl-CoA dehydrogenase is required for catabolism of isoleucine, valine and short-chain fatty acids in Aspergillus nidulans. 1765 40
Short/branched chain
acyl-CoA dehydrogenase
(SBCAD), isovaleryl-CoA dehydrogenase (IVD), and isobutyryl-CoA dehydrogenase (IBD) are involved in metabolism of isoleucine, leucine, and
valine
, respectively. These three enzymes all belong to
acyl-CoA dehydrogenase
(
ACD
) family, and catalyze the dehydrogenation of monomethyl branched-chain fatty acid (mmBCFA) thioester derivatives. In the present work, the catalytic properties of rat SBCAD, IVD, and IBD, including their substrate specificity, isomerase activity, and enzyme inhibition, were comparatively studied. Our results indicated that SBCAD has its catalytic properties relatively similar to those of straight-chain acyl-CoA dehydrogenases in terms of their isomerase activity and enzyme inhibition, while IVD and IBD are different. IVD has relatively broader substrate specificity than those of the other two enzymes in accommodating various substrate analogs. The present study increased our understanding for the metabolism of monomethyl branched-chain fatty acids (mmBCFAs) and branched-chain amino acids (BCAAs), which should also be useful for selective control of a particular reaction through the design of specific inhibitors.
...
PMID:Comparative studies of Acyl-CoA dehydrogenases for monomethyl branched chain substrates in amino acid metabolism. 2347 14
Bio-based isobutantol is a sustainable 'drop in' substitute for petroleum-based fuels. However, well-studied production routes, such as the Ehrlich pathway, have yet to be commercialized despite more than a century of research. The more versatile bacterial
valine
catabolism may be a competitive alternate route producing not only an isobutanol precursor but several carboxylic acids with applications as biomonomers, and building blocks for other advanced biofuels. Here, we transfer the first two committed steps of the pathway from pathogenic
Pseudomonas aeruginosa
PAO1 to yeast to evaluate their activity in a safer model organism. Genes encoding the heteroligomeric branched chain keto-acid dehydrogenase (BCKAD;
bkdA1, bkdA2, bkdB, lpdV
), and the homooligomeric
acyl-CoA dehydrogenase
(ACD;
acd1
) were tagged with fluorescence epitopes and targeted for expression in either the mitochondria or cytoplasm of
S. cerevisiae
. We verified the localization of our constructs with confocal fluorescence microscopy before measuring the activity of tag-free constructs. Despite reduced heterologous expression of mitochondria-targeted enzymes, their specific activities were significantly improved with total enzyme activities up to 138% greater than those of enzymes expressed in the cytoplasm. In total, our results demonstrate that the choice of protein localization in yeast has significant impact on heterologous activity, and suggests a new path forward for isobutanol production.
...
PMID:Mitochondrial targeting increases specific activity of a heterologous valine assimilation pathway in
Saccharomyces cerevisiae
. 2946 14
Branched chain amino acid (BCAA) metabolism occurs within the mitochondrial matrix and is comprised of multiple enzymes, some shared, organized into three pathways for the catabolism of leucine, isoleucine, and
valine
(LEU, ILE, and
VAL
respectively). Three different acyl-CoA dehydrogenases (ACADs) are active in each catabolic pathway and genetic deficiencies in each have been identified. While characteristic metabolites related to the enzymatic block accumulate in each deficiency, for reasons that are not clear, clinical symptoms are only seen in the context of deficiency of isovaleryl-CoA dehydrogenase (IVDH) in the leucine pathway. Metabolism of fibroblasts derived from patients with mutations in each of the BCAA ACADs were characterized using metabolomics to better understand the flux of BCAA through their respective pathways. Stable isotope labeled LEU, ILE, and
VAL
in patient and control cell lines revealed that mutations in isobutyryl-CoA dehydrogenase (IBDH in the
valine
pathway) lead to a significant increase in isobutyrylcarnitine (a surrogate for the enzyme substrate isobutyryl-CoA) leading to metabolism by short-branched chain
acyl-CoA dehydrogenase
(SBCADH in the isoleucine pathway) and production of the pathway end product propionylcarnitine (a surrogate for propionyl-CoA). Similar cross activity was observed for SBCADH deficient patient cells, leading to a significant increase in propionylcarnitine, presumably by metabolism of 2 methylbutyryl-CoA via IBDH activity. Labeled BCAA studies identified that the majority of the intracellular propionyl-CoA pool in fibroblasts is generated from isoleucine, but heptanoic acid (a surrogate for odd-chain fatty acids) is also efficiently converted to propionate.
...
PMID:Metabolic analysis reveals evidence for branched chain amino acid catabolism crosstalk and the potential for improved treatment of organic acidurias. 3113 29
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