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:1.3.5.1 (succinate dehydrogenase)
8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cytochrome c oxidase (CCO) has been histochemically studied in 250 muscle biopsies from patients with different neuromuscular diseases. The results were compared with those obtained on serial sections stained with Gomori's trichrome and with the methods for NADH tetrazolium reductase, succinate dehydrogenase and lactate dehydrogenase. In 58 selected cases serial sections were also stained with a method demonstrating coenzyme Q (CoQ) activity. Demonstration of structural alterations was as good with CCO as with the methods for other oxidative enzymes: particularly evident were alterations of the distribution of mitochondria, such as core areas in central core and multiminicore diseases. Unstained fibers were observed in mitochondrial myopathies, in Becker, Emery-Dreifuss, limb-girdle, facio-scapulo-humeral muscular dystrophies, muscle infarction, polymyositis, motor neuron diseases and neuropathies. The histochemical method for CoQ showed only low specificity, since partial staining was also present in areas devoid of mitochondria, such as cores. CoQ deficiency was not observed in any of the 19 mitochondrial myopathies examined.
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PMID:Cytochrome c oxidase and coenzyme Q in neuromuscular diseases: a histochemical study. 196 58

The activity of the mitochondrial glycerol phosphate dehydrogenase (EC 1.1.99.5), the enzyme unique to the glycerol phosphate hydrogen shuttle, was measured in normal human tissues and tumors and compared with the activity of succinate dehydrogenase, another enzyme that transfers electrons to ubiquinone at site II of the electron transport chain. Six of 7 insulinomas and 10 of 12 carcinoid tumors showed high glycerol phosphate dehydrogenase activity. The activity was also increased in 3 of 4 gastrinomas, 2 paraganglionomas, 1 of 4 thyroid nodules, and 1 parathyroid tumor. These tissues belong to the amine precursor uptake decarboxylation system. The activity of glycerol phosphate dehydrogenase was generally unremarkable in non-amine precursor uptake decarboxylation system tumors and in normal tissues studied. However, 1 of 2 breast carcinomas, 1 submandibular tumor, and 2 of 3 melanomas were enriched in glycerol phosphate dehydrogenase activity. In general, succinate dehydrogenase activity exceeded that of glycerol phosphate dehydrogenase in all tissues except some of the tissues in which glycerol phosphate dehydrogenase activity was high. Normal tissues, such as the pancreatic beta-cell, which aerobically metabolize glucose rapidly utilize the glycerol phosphate shuttle to oxidize the large amount of NADH formed from glucose metabolism in the cytosol. Whether this is the reason for the enriched activity of the glycerol phosphate dehydrogenase in certain amine precursor uptake decarboxylation system tumors is unknown.
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PMID:High activity of mitochondrial glycerol phosphate dehydrogenase in insulinomas and carcinoid and other tumors of the amine precursor uptake decarboxylation system. 197 16

Exposure of isolated mouse hepatocytes to a toxic concentration of acetaminophen (5 mM) resulted in damage to the mitochondrial respiratory apparatus. The nature of this damage was investigated by measuring respiration stimulated by site-specific substrates in digitonin-permeabilized hepatocytes after acetaminophen exposure. Respiration stimulated by succinate at energy-coupling site 2 was most sensitive to inhibition and was decreased by 47% after 1 h. Respiration supported by NADH-linked substrates (site 1) was also decreased but to a lesser extent, while there was no decrease in the rate of ascorbate + N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD)-supported respiration (site 3). The loss of mitochondrial respiratory function was accompanied by a decrease in ATP levels and ATP/ADP ratios in the cytosolic compartment and was preceded by a loss of reduced glutathione in both the cytosol and mitochondria. All these effects occurred well before the loss of cell membrane integrity. The putative toxic metabolite of acetaminophen, N-acetyl-p-benzoquinonimine (NAPQI), produced a similar pattern of respiratory dysfunction in isolated hepatic mitochondria. Respiration stimulated by succinate- and NADH-linked substrates was very sensitive to 50 microM NAPQI, while ascorbate + TMPD-supported respiration was unaffected. The interaction between NAPQI and the respiratory chain was further investigated using submitochondrial particles. Succinate dehydrogenase (associated with respiratory complex II) was found to be very sensitive to NAPQI, while NADH dehydrogenase (respiratory complex I) was inhibited to a lesser extent. Our results indicate that a loss of the ability to utilize succinate- and NADH-linked substrates due to attack of the respiratory chain by NAPQI causes a disruption of energy homeostasis in acetaminophen hepatotoxicity.
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PMID:Acetaminophen toxicity results in site-specific mitochondrial damage in isolated mouse hepatocytes. 200 47

The involvement of a quinone in the antimycin A-insensitive electron transfer from NADH-dehydrogenase to cytochrome c via the alternative respiratory chain of Candida parapsilosis, by-passing complex II, has been studied. After a partial extraction of quinones, the residual respiration was fully antimycin-A-sensitive, but reincorporation of the organic extract partially restored an antimycin A-insensitive respiration. Analysis of quinone content by HPLC, after purification by thin-layer chromatography, evidenced another quinone species in a very low amount. Myxothiazol and stigmatellin were shown to inhibit the alternative pathway but at a higher concentration than required to inhibit the classical pathway. Cytochrome spectra analysis showed that, in the presence of high myxothiazol concentrations, cytochromes c and aa3 were not reduced, while they were in the presence of antimycin A. It is suggested that the secondary pathway of C. parapsilosis involved a specific quinone pool which can be displaced from its binding site by high concentrations of myxothiazol or analogous compounds.
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PMID:The antimycin-A-insensitive respiratory pathway of Candida parapsilosis: evidence for a second quinone involved specifically in its functioning. 200 73

In the present study three techniques for obtaining outer membrane enriched fractions from Yersinia pestis were evaluated. The techniques analysed were: differential solubilization of the cytoplasmic membrane with Sarkosyl or Triton X-100, and centrifugation in sucrose density gradients. The sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of outer membrane isolated by the different methods resulted in similar protein patterns. The measurement of NADH-dehydrogenase and succinate dehydrogenase (inner membrane enzymes) indicated that the outer membrane preparations obtained by the three methods were pure enough for analytical studies. In addition, preliminary evidences on the potential use of outer membrane proteins for the identification of geographic variants of Y. pestis wild isolates are presented.
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PMID:Comparative studies of Yersinia pestis outer membrane isolation techniques and their potential use in plaque epidemiology. 209 28

The question was investigated as to whether the bacterial menaquinone (MK) is a component of the electron transport chain catalyzing succinate respiration in Bacillus subtilis. Three different methods were applied, and the following consistent results were obtained. (i) Solvent extraction of MK from the bacterial membrane caused total inhibition of the respiratory activities with succinate and NADH, while the activity of succinate dehydrogenase remained unaffected. The respiratory activities were restored on incorporation of vitamin K1 into the membrane preparation. (ii) The membrane fraction of a B. subtilis mutant containing 15% of the wild-type amount of MK, respired succinate and NADH at reduced activities. Wild-type activities were restored on fusion of the preparation to liposomes containing vitamin K1. (iii) The membrane fraction of B. subtilis catalyzed succinate oxidation by various water-soluble naphtho- or benzoquinones at specific activities exceeding to that of succinate respiration. The results suggest that MK is involved in succinate respiration, although its redox potential is unfavorable.
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PMID:Menaquinone is an obligatory component of the chain catalyzing succinate respiration in Bacillus subtilis. 212 69

During accommodation, the ciliary muscle is known to move forward-inward. This movement depends on the stiffness of the ciliary muscle connections with the scleral spur. These connections are mediated by the tips of the meridional muscle. If the tips are weakened by pharmacological or surgical means, accommodation suffers. For normal accommodation, it is therefore necessary that the tips stiffen before the contraction of the main part of the muscle. We have therefore looked at the primate eye for enzymatic and ultrastructural differences between the tips and the bulk of the muscle viz, the reticular and circular portion. Myosin ATPase was stained after either alkaline or acid preincubation. Lactate dehydrogenase (LDH), succinic dehydrogenase (SDH), NADH-tetrazoliumreductase (TR) and lipids were stained using conventional methods. The results of the enzyme staining were a modest difference between the meridional tips and the bulk. The tips stained stronger for ATPase following both preincubation methods, and for LDH, whereas the bulk cells stained stronger for SDH, NADH-TR and lipids. The tips contained fewer mitochondria and more myofibrils. In all these respects, the tips of the meridional muscle resemble the fast fibers of striated muscle.
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PMID:Histochemical differences within the ciliary muscle and its function in accommodation. 213 92

We report the morphological, biochemical, immunological, and genetic findings in a patient with the clinical characteristics of Leigh's disease due to multisystemic cytochrome c oxidase (CCO) deficiency. Muscle biopsy at 2 years and 5 months of age showed markedly decreased CCO and cytochrome a + a3, moderately decreased NADH-cytochrome c reductase to 46.3%, and generalized loss of immunologically detectable CCO subunits, but other respiratory chain enzyme proteins were normal. All the tissues examined at autopsy showed decreased activity of all respiratory chain enzymes except complex II. The decrease in cytochromes b and a + a3 were in harmony with decreased enzyme activities in complex III and IV (CCO), respectively. All immunologically detectable subunits of CCO in immunoprecipitation were uniformly decreased in the cardiac and skeletal muscles, but subunits 1 and 4 were selectively decreased in other organs except liver. No large deletion could be detected in the cardiac muscle mtDNA after digestion with restriction enzymes. These results suggest that the respiratory chain enzymes are variable in their activity and the amount of enzyme proteins decreases as the disease progresses.
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PMID:Progressive cytochrome c oxidase deficiency in a case of Leigh's encephalomyelopathy. 215 85

Bovine heart submitochondrial particles (SMP) were exposed to continuous fluxes of hydroxyl radical (.OH) alone, superoxide anion radical (O2-) alone, or mixtures of .OH and O2-, by gamma radiolysis in the presence of 100% N2O (.OH exposure), 100% O2 + formate (O2- exposure), or 100% O2 alone (.OH + O2- exposure). Hydrogen peroxide effects were studied by addition of pure H2O2. NADH dehydrogenase, NADH oxidase, succinate dehydrogenase, succinate oxidase, and ATPase activities (Vmax) were rapidly inactivated by .OH (10% inactivation at 15-40 nmol of .OH/mg of SMP protein, 50-90% inactivation at 600 nmol of .OH/mg of SMP protein) and by .OH + O2- (10% inactivation at 20-80 nmol of .OH + O2-/mg of SMP protein, 45-75% inactivation at 600 nmol of .OH + O2-/mg of SMP protein). Importantly, O2- was a highly efficient inactivator of NADH dehydrogenase, NADH oxidase, and ATPase (10% inactivation at 20-50 nmol of O2-/mg of SMP protein, 40% inactivation at 600 nmol of O2-/mg of SMP protein), a mildly efficient inactivator of succinate dehydrogenase (10% inactivation at 150 nmol of O2-/mg of SMP protein, 30% inactivation at 600 nmol of O2-/mg of SMP protein), and a poor inactivator of succinate oxidase (less than 10% inactivation at 600 nmol of O2-/mg of SMP protein). H2O2 partially inactivated NADH dehydrogenase, NADH oxidase, and cytochrome oxidase, but even 10% loss of these activities required at least 500-600 nmol of H2O2/mg of SMP protein. Cytochrome oxidase activity (oxygen consumption supported by ascorbate + N,N,N',N'-tetramethyl-p-phenylenediamine) was remarkably resistant to oxidative inactivation, with less than 20% loss of activity evident even at .OH, O2-, OH + O2-, or H2O2 concentrations of 600 nmol/mg of SMP protein. Cytochrome c oxidase activity, however (oxidation of, added, ferrocytochrome c), exhibited more than a 40% inactivation at 600 nmol of .OH/mg of SMP protein. The .OH-dependent inactivations reported above were largely inhibitable by the .OH scavenger mannitol. In contrast, the O2(-)-dependent inactivations were inhibited by active superoxide dismutase, but not by denatured superoxide dismutase or catalase. Membrane lipid peroxidation was evident with .OH exposure but could be prevented by various lipid-soluble antioxidants which did not protect enzymatic activities at all.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The oxidative inactivation of mitochondrial electron transport chain components and ATPase. 216 88

Brain mitochondrial enzyme activities were examined in 15-day-old suckling mice which were daily injected with D-penicillamine (DP), a chelating agent of copper. Newborn mice treated with DP (1 g/kg/day) showed retarded weight gain, hyperelasticity of skin, and a bizarre forelimb posture with subcutaneous edema on experimental day (ED) 7. Paraparesis or dragging of the hindlimbs was observed by ED 15. Brain copper contents of DP-treated mice decreased to 34% of the controls of ED 15. Cytochrome c oxidase activity (complex IV) in the brain showed 51% decrease of the controls, on the contrary, rotenone-sensitive NADH cytochrome c reductase (complex I + III) and succinate cytochrome c reductase (complex II + III) were normal. Histochemistry of cytochrome c oxidase in the cerebellum of DP-treated mice disclosed diffuse reduction of staining, especially in Purkinje cells. These data show that DP-induced copper deficiency in the brain subsequently disturbs mitochondrial electron transport system, selectively cytochrome c oxidase activity. This seems to be a useful animal model not only for Menkes' kinky hair disease but also for mitochondrial encephalomyopathy.
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PMID:D-penicillamine-induced copper deficiency in suckling mice: neurological abnormalities and brain mitochondrial enzyme activities. 217 57


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