Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.3.5.1 (succinate dehydrogenase)
 8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Monoamine oxidase (MAO) increases in an age-weight relationship in the hearts of male rats. Accumulation of MAO is not related to the activities of such mitochondrial enzymes as succinic dehydrogenase or cytochrome oxidase which do not change with age. Our previous experiments, utilizing serotonin as a substrate, have determined that cardiac MAO in the young rat does not change after chemical sympathetectomy with 6-hydroxydopamine. In this study, rats of different ages were treated with 6-hydroxy-dopamine to investigate the neuronal vs. non-neuronal distribution of MAO in the heart. After sympathetectomy, various parts of the hearts and fractions of the hearts isolated by differential centrifugation were tested for changes in MAO activity with two different substrates (kynuramine and 14C-tryptamine). It was not possible to detect any changes in MAO activity in any parts or subcellular fractions of the heart as a result of denervation. Studies with clorgyline, the MAO inhibitor, in control and sympathetecomized animals revealed that rat cardiac MAO is mostly of the type A enzyme, which was originally thought to be neuronal. A histochemical technique for the electron microscopic demonstration of MAO with osmiophilic thiocarbamyl nitro blue tetrazolium was used in the rat heart in order to determine the ultrastructural location of the enzyme. Histochemical localization of MAO with the electron microscope using tryptamine as the substrate indicates that a substantial portion of rat cardiac MAO is located near the outer membranes of mitochondria within myocardial cells. This histochemical technique provides no evidence to support differential centrifugation data which suggests the presence of a sarcoplasmic reticular (microsomal) MAO in rat heart.
J Pharmacol Exp Ther 1975 Sep
PMID:Extraneuronal monoamine oxidase in rat heart: biochemical characterization and electron microscopic localization. 115 29

Mitochondrial myopathies are morphologically characterized by ragged-red fibres (RRF). Serial cross-section revealed that the ragged-red appearance was only focal. This is in agreement with a partial cytochrome c oxidase (COX) deficiency in chronic progressive external ophthalmoplegia (CPEO). Since most of these patients show deletions of the mitochondrial genome single fibre analyses were performed determining COX and succinate dehydrogenase (SDH) in serial muscle sections from two patients with CPEO. High SDH activity was demonstrated in RRF; in contrast COX activity was lower in RRF in a patient, possibly representing a focal assembly of mitochondria with deletions in their genomes. The variation of enzyme activities along the muscle fibre was especially high in RRF. This study presents the first quantitative evidence that enzyme activities vary considerably along fibres in muscle from patients with a mitochondrial myopathy.
Histochemistry 1992 Sep
PMID:Enzyme activity analyses along ragged-red and normal single muscle fibres. 133 Sep 95

A simple and rapid low speed density gradient centrifugation method has been described to isolate relatively pure synaptosomes and non-synaptic mitochondria from rat brain cerebral cortex. The purity of the fractions isolated were tested biochemically by considering some marker enzymes, i.e., lactate dehydrogenase, plasma membrane Na+K+ATPase and acetylcholinesterase for the synaptosomes and succinate dehydrogenase for the mitochondrial fraction. The adrenergic receptor properties in the synaptosomal membrane were evaluated by observing the effect of different beta- and alpha 2-adrenergic receptor agonists and antagonists as function of synaptic plasma membrane Na+K+ATPase activity. Isoproterenol (beta-agonist) and yohimbine (alpha 2-antagonist)-induced changes in the synaptosomal Na+K+ATPase activity were counteracted by beta-antagonist propranolol and alpha 2-agonist clonidine, respectively. In the non-synaptic mitochondria the corresponding effects were insignificant. The study illustrates an easy, rapid and low-speed preparatory method to obtain synaptosomal and non-synaptic mitochondrial fractions of high purity.
Methods Find Exp Clin Pharmacol 1992 Sep
PMID:A simple biochemical approach to differentiate synaptosomes and non-synaptic mitochondria from rat brain. 133 69

The unicellular green alga Dunaliella bardawil responds to high light, nutrient deprivation, and several other types of stress by massive accumulation of beta-carotene. We have previously cloned a nuclear gene, cbr, that is co-induced with accelerated carotenogenesis. The predicted product of cbr is closely related to early light-induced proteins (Elips) of higher plants, and also shows resemblance to chlorophyll a/b-binding proteins. In the present study, the determination of the cbr transcription start site supported the previously proposed site of translation initiation. Antibodies raised against a synthetic oligopeptide matching the predicted sequence of Cbr recognized two polypeptides of apparently 17 and 19 kDa that were induced in parallel to cbr transcript accumulation in highly illuminated or sulfate-starved D. bardawil cells. The antibodies also cross-reacted with an approximately 20-kDa polypeptide in sulfate-starved Dunaliella salina. In both D. bardawil and D. salina, Cbr was found exclusively in the thylakoid membranes. After mild solubilization, Cbr co-fractionated with light-harvesting complex II (LHCII) in sucrose gradient centrifugation and gel electrophoresis and was specifically associated with a minor LHCII complex. An occasionally observed, faster mobility Cbr form, free of LHCII, was probably released from the larger complex. These results support the conclusion that Cbr belongs to a class of stress-induced proteins transiently associated with antennae complexes.
J Biol Chem 1992 Sep 15
PMID:Regulation and light-harvesting complex II association of a Dunaliella protein homologous to early light-induced proteins in higher plants. 138 63

Site-directed mutagenesis was used to introduce mutations into the gene for the iron protein (IP) of succinate dehydrogenase (SDH) of Saccharomyces cerevisiae. Specifically, three mutations were examined which caused the synthesis of truncated IP peptides missing four, seven, or 17 amino acids from the C-terminus, respectively. The deletion of seven or more amino acids includes the loss of two lysine residues, which appear to have been highly conserved in evolution. While the deletion of four amino acids had no effect on the assembly of complex II and on its activity, the deletion including the two lysines abolished SDS activity completely and led to the failure of the imported IP peptide to be incorporated into a stable complex II or SDH complex. Replacement of one of the lysines by threonine had no effect, but replacement of both by threonine affected the specific activity of complex II but not its assembly and stability.
Biochemistry 1992 Sep 15
PMID:The C-terminus of the succinate dehydrogenase IP peptide of Saccharomyces cerevisiae is significant for assembly of complex II. 139 Jun 28

Patients with a hereditary mitochondrial myopathy with succinate dehydrogenase (SDH) deficiency and abnormal lactacidosis during physical exercise have a low work capacity when exercising for about 10-15 min. Their maximum voluntary muscular strength is fairly normal. The relationship between the time (t) and a constant workload (N) that a healthy subject can maximally sustain can be expressed as: log t = beta + alpha log N. For normal subjects the constant alpha is approximately -5 and the constant beta has a large interindividual variation. Of four myopathy patients alpha was determined from two or three maximum bicycle exercise tests of different duration (including ramp- and steady-state tests using a new application of the method of adding submaximal loads to the final maximum workload). The value of alpha varied between -1.0 and -1.81 and beta had low values, both significantly different from those of healthy subjects. The alpha values explain the divergent results that may be obtained with different types of exercise tests in some of these patients, i.e. a normal or moderately reduced capacity in exercise tests of short duration (for example a short Tornvall or a ramp type of test) and a very low exercise capacity in tests of longer duration (for example a steady state type of test with workloads chosen to allow at least two loads). The low absolute value of alpha may be related to the abnormally increased anaerobic metabolism of these patients during exercise, caused by the SDH deficiency.
Clin Physiol 1992 Sep
PMID:Dependence of maximum performance time on work intensity in patients with a hereditary myopathy with succinate dehydrogenase deficiency. 139 48

Adult male rats were treated intraperitoneally with chloroquine (5 mg/kg/day) for 9 days. A reduction in the fasting plasma glucose level by 17.6% and ascorbic acid by 45% were discernable. The treatment caused significant increase in liver lactate dehydrogenase and glucose-6-phosphate dehydrogenase activities and reduced the activity of succinate dehydrogenase enzyme. Chloroquine also caused significant reductions in the contents of reduced glutathione and ascorbic acid in the brain and erythrocytes with a significant increase in lipid peroxidation.
Pharmacol Toxicol 1992 Sep
PMID:Effect of chloroquine on some carbohydrate metabolic pathways: contents of GHS, ascorbate and lipid peroxidation in the rat. 143 36

We describe the isolation, sequence and construction of a disruption of the yeast SDH1 gene, encoding the flavoprotein subunit of succinate dehydrogenase. This is the first eukaryotic flavoprotein subunit-encoding gene to be fully sequenced. The deduced amino acid (aa) sequence is 50% identical to the Escherichia coli enzyme sequence. The yeast gene encodes an N-terminal extension of 45 aa relative to the E. coli sequence which may act as a mitochondrial targeting signal. Disruption of the gene results in the inability to respire, assayed as the inability to utilize the nonfermentable carbon source, glycerol. This is the expected phenotype for disruption of an essential component of the yeast citric acid cycle.
Gene 1992 Sep 01
PMID:SDH1, the gene encoding the succinate dehydrogenase flavoprotein subunit from Saccharomyces cerevisiae. 151 76

We have isolated a homolog for the flavoprotein subunit of succinate dehydrogenase [succinate:(acceptor) oxidoreductase, EC 1.3.99.1] from Saccharomyces cerevisiae and used the obtained peptide sequences to clone and characterize the corresponding gene. It contained an open reading frame of 1923 base pairs and encoded a protein of 640 amino acids (M(r), 70,238) that showed approximately 49% and approximately 28% identity with the Escherichia coli and Bacillus subtilis enzymes, respectively. All features of the FAD cofactor binding site were completely conserved. Comparison of the deduced protein sequence with the N-terminal sequence determined from the isolated protein revealed an N-terminal extension of 28 amino acids that presumably represents a mitochondrial signal sequence. After in vitro transcription and translation, the preprotein was efficiently imported into isolated yeast mitochondria, cleaved to its mature form, and assembled into the membrane-bound succinate dehydrogenase complex.
Proc Natl Acad Sci U S A 1992 Sep 01
PMID:Primary structure, import, and assembly of the yeast homolog of succinate dehydrogenase flavoprotein. 151 27

We have compared the size and arrangement of the primary somatic sensory cortex (SI) and its constituent parts in juvenile (1 week old) and mature (10-12 weeks old) rats using succinic dehydrogenase histochemistry and digital image analysis. Our goal was to determine whether some regions of the maturing cortex grow more than others. To this end, we examined (1) the growth of barrels and the surrounding (interbarrel) cortex, (2) the growth of the major somatic representations within SI, and (3) the overall growth of SI compared to the neocortex as a whole. With respect to the first of these issues, SI barrels and barrel-like structures grow more than the intervening cortex. The growth of these elements varies according to region: barrels in the head representation more than double in size, whereas the barrel-like structures in the paw representations increase by only about half this amount. The growth of the major somatic representations within SI is also heterogeneous, the representation of the head enlarging to a greater extent than the representations of the paws. Thus, the ratio of the total area of head representation to the combined paw representation is 15% greater in adults than in juveniles. Finally, the primary somatic sensory cortex grows to a somewhat greater extent than the neocortex as a whole. These observations demonstrate that postnatal cortical growth is not uniform; it varies among cortical barrels and the immediately surrounding (interbarrel) cortex, among the representations of different body parts, and between SI and the rest of the neocortex. As an explanation of this differential growth, we suggest that the neuropil of metabolically (and/or electrically) more active cortical regions grows to a greater extent during maturation than that of less active regions.
J Neurosci 1992 Sep
PMID:Growth of the rat somatic sensory cortex and its constituent parts during postnatal development. 152 93


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>