scholarly journals Inhibition of peroxisomal fatty acyl-CoA oxidase by antimycin A

1987 ◽  
Vol 248 (2) ◽  
pp. 603-607 ◽  
Author(s):  
J Vamecq ◽  
L Schepers ◽  
G Parmentier ◽  
G P Mannaerts

Peroxisomal fatty acyl-CoA oxidase was inhibited by micromolar concentrations of antimycin A, an inhibitor of mitochondrial respiration. The inhibition was observed with all three substrates tested, i.e. palmitoyl-CoA, trihydroxycoprostanoyl-CoA and hexadecanedioyl-CoA. The peroxisomal D-amino acid oxidase was also inhibited by antimycin, but the peroxisomal L-alpha-hydroxyacid oxidase and uric acid oxidase and the mitochondrial monoamine oxidase were not. The degree of inhibition of acyl-CoA oxidase by antimycin was strongly dependent on the amount of cellular protein present in the assay mixture: at a fixed antimycin concentration, the inhibition was gradually lost with increasing protein concentrations. At a fixed cellular protein concentration in the assay mixtures, the mitochondrial oxidation of glutamate or palmitoylcarnitine was inhibited at antimycin concentrations that were much lower than those required for the inhibition of fatty acyl-CoA oxidase. Our results, nevertheless, demonstrate that antimycin A must be used with caution, when it is added to homogenates or subcellular fractions in order to distinguish between mitochondrial and peroxisomal fatty acid oxidation.

1985 ◽  
Vol 227 (1) ◽  
pp. 205-210 ◽  
Author(s):  
G M Small ◽  
K Burdett ◽  
M J Connock

A simple spectrophotometric assay was developed for peroxisomal fatty acyl-CoA oxidase activity. The assay, based on the H2O2-dependent oxidation of leuco-dichlorofluorescein catalysed by exogenous peroxidase, is more sensitive than methods previously described. By using mouse liver samples, cofactor requirements were assessed and a linear relationship was demonstrated between dye oxidation and enzyme concentration. By using this assay on subcellular fractions, palmitoyl-CoA oxidase activity was localized for the first time in microperoxisomes of rat intestine. The assay was also adapted to measure D-amino acid oxidase activity, demonstrating the versatility of this method for measuring activity of other H2O2-producing oxidases.


1977 ◽  
Vol 55 (1) ◽  
pp. 66-74 ◽  
Author(s):  
Melvin G. Rosenfeld ◽  
Edward H. Leiter

D-Amino acid oxidase (EC 1.4.3.3) activity in homogenates of Neurospora crassa strain SY7A was found to sediment with the mitochondrial fraction. Digitonin fractionation studies on purified mitochondria have indicated a matrix localization of the enzyme. Additionally, a peroxidase (EC 1.11.1.7) activity, which may remove hydrogen peroxide formed as a product of D-amino acid oxidation, was also found in the mitochondrial matrix.Partial purification (20- to 30-fold) of the mitochondrial D-amino acid oxidase was achieved. The enzyme exhibited a pH optimum between 9.0 and 9.2, temperature optimum between 20 and 30 °C, and a molecular weight of 118 000 ± 6000 as determined by gel electrophoresis and 125 000 as determined by gel chromatography.


2005 ◽  
Vol 5 (6) ◽  
pp. 550-555 ◽  
Author(s):  
Z. Findrik ◽  
D. Vasić-Rački ◽  
B. Geueke ◽  
M. Kuzu ◽  
W. Hummel

1988 ◽  
Vol 107 (3) ◽  
pp. 897-905 ◽  
Author(s):  
S J Gould ◽  
G A Keller ◽  
S Subramani

As part of an effort to understand how proteins are imported into the peroxisome, we have sought to identify the peroxisomal targeting signals in four unrelated peroxisomal proteins: human catalase, rat hydratase:dehydrogenase, pig D-amino acid oxidase, and rat acyl-CoA oxidase. Using gene fusion experiments, we have identified a region of each protein that can direct heterologous proteins to peroxisomes. In each case, the peroxisomal targeting signal is contained at or near the carboxy terminus of the protein. For catalase, the peroxisomal targeting signal is located within the COOH-terminal 27 amino acids of the protein. For hydratase:dehydrogenase, D-amino acid oxidase, and acyl-CoA oxidase, the targeting signals are located within the carboxy-terminal 15, 14, and 15 amino acids, respectively. A tripeptide of the sequence Ser-Lys/His-Leu is present in each of these targeting signals as well as in the peroxisomal targeting signal identified in firefly luciferase (Gould, S.J., G.-A. Keller, and S. Subramani. 1987. J. Cell Biol. 105:2923-2931). When the peroxisomal targeting signal of the hydratase:dehydrogenase is mutated so that the Ser-Lys-Leu tripeptide is converted to Ser-Asn-Leu, it can no longer direct proteins to peroxisomes. We suggest that this tripeptide is an essential element of at least one class of peroxisomal targeting signals.


Author(s):  
Catherine A. Taylor ◽  
Bruce M. Jarnot

Peroxisome induction can be expressed as an increase in peroxisome area (proliferation) or as an increase in peroxisomal fatty acid oxidation (activity). This study compares proliferation and activity as endpoints for hepatic peroxisome induction by perfluorodecanoic acid (PFDA). Fluorocarboxylic acids such as PFDA represent a class of compounds possessing commercially important surfactant properties. A single 50 mg/Kg ip. dose of PFDA produces a characteristic “wasting syndrome” in male F-344 rats. Symptoms include hypophagia, weight loss, hepatomegaly, and delayed lethality. Hepatic studies reveal changes similar to those seen with the hypolipidemic agent clofibrate. These include mitochondrial disruption, endoplasmic reticulum and peroxisome proliferation, and increased peroxisomal acyl-CoA oxidase activity.Male Fisher-344 rats received a single ip. dose of 2, 20, or 50mg/Kg PFDA dissolved in 1:1 propylene glycol/water and were sacrificed 8 days post-dose. All control rats received an equal volume of vehicle ip. Animals were provided food and water ad libitum, except pair-fed controls which received the same restrictive food intake consumed by their weight-paired dosed partners (50mg/Kg PFDA group) to simulate the hypophagia associated with PFDA.


1996 ◽  
Vol 76 (06) ◽  
pp. 0993-0997
Author(s):  
Zhao-Yan Li ◽  
Xiao-Wei Wu ◽  
Tie-Fu Yu ◽  
Eric C-Y Lian

SummaryBy means of CM-Sephadex C-25, DEAE-Sephadex A-50, Sephadex G-200, and Sephadex G-75 chromatographies, a lupus anticoagulant like protein (LALP) from Agkistrodon halys brevicaudus was purified. On SDS-PAGE, the purified LALP had a molecular weight of 25,500 daltons under non-reducing condition and 15,000 daltons under reducing condition. The isoelectric point was pH 5.6. Its N terminal amino acid sequencing revealed a mixture of 2 sequences: DCP(P/S)(D/G)WSSYEGH(C/R)Q(Q/K). It was devoid of phospho-lipaseA, fibrino(geno)lytic, 5′-nucleotidase, L-amino acid oxidase, phosphomonoesterase, phosphodiesterase and thrombin-like activities, which were found in crude venom. In the presence of LALP, PT, aPTT, and dRVVT of human plasma were markedly prolonged and its effects were concentration-dependent but time-independent. The inhibitory effect of LALP on the plasma clotting time was enhanced by decreasing phospholipid concentration in TTI test. The individual clotting factor activity was not affected by LALP when higher dilutions of LALP-plasma mixture were used for assay. Russell’s viper venom time was shortened when high phospholipid confirmatory reagent was used. Therefore, the protein has lupus anticoagulant property.


1982 ◽  
Vol 48 (03) ◽  
pp. 277-282 ◽  
Author(s):  
I Nathan ◽  
A Dvilansky ◽  
T Yirmiyahu ◽  
M Aharon ◽  
A Livne

SummaryEchis colorata bites cause impairment of platelet aggregation and hemostatic disorders. The mechanism by which the snake venom inhibits platelet aggregation was studied. Upon fractionation, aggregation impairment activity and L-amino acid oxidase activity were similarly separated from the crude venom, unlike other venom enzymes. Preparations of L-amino acid oxidase from E.colorata and from Crotalus adamanteus replaced effectively the crude E.colorata venom in impairment of platelet aggregation. Furthermore, different treatments known to inhibit L-amino acid oxidase reduced in parallel the oxidase activity and the impairment potency of both the venom and the enzyme preparation. H2O2 mimicked characteristically the impairment effects of L-amino acid oxidase and the venom. Catalase completely abolished the impairment effects of the enzyme and the venom. It is concluded that hydrogen peroxide formed by the venom L-amino acid oxidase plays a role in affecting platelet aggregation and thus could contribute to the extended bleeding typical to persons bitten by E.colorata.


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