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)

The isolation is described of pure cultures of three non-methane-utilizing methylotrophic bacteria which, together with the previously described Bacillus PM6, have a very limited range of growth substrates; these organisms are designated "restricted facultative' methylotrophs. Two of these isolates, W6A and W3A1, grow only on glucose out of 50 non-C1 compounds tested, whereas the third isolate S2A1 and Bacillus PM6 grow on betaine, glucose, gluconate, alanine, glutamate, citrate and nutrient agar, but not on any of a further 56 non-C1 compounds. Crude sonic extracts of trimethylamine-grown and glucose-grown W6A and W3A1 isolates, and of trimethylamine-grown C2A1 (an obligate methylotroph) contain (i) no detectable 2-oxogltarate dehydrogenase activity, (ii) very low or zero specific activities of succinate dehydrogenase and succinyl-CoA synthetase and (iii) NAD+-dependent isocitrate dehydrogenase activity. Extracts of trimethylamine-grown PM6 and S2A1 methylotrophs have (i) very low 2-oxoglutarate dehydrogenase specific activities, (ii) comparatively high specific activities of succinate dehydrogenase, malate dehydrogenase and succinyl-CoA synthetase and (iii) NADP+-dependent isocitrate dehydrogenase activity but no NAD+-dependent isocitrate dehydrogenase activity. The activities of most of these enzymes are increased during growth on glucose, alanine, glutamate or citrate, but only very low 2-oxoglutarate dehydrogenase activities are present under all growth conditions. The restricted facultative methylotrophs grow on certain non-C1 compounds in the absence of 2-oxoglutarate dehydrogenase and, in some cases, of other enzymes of the tricarboxylic acid cycle; these lesions cannot therefore be the sole cause of obligate methylotrophy.
 ...
PMID:Tricarboxylic acid-cycle and related enzymes in restricted facultative methylotrophs. 0 Sep 91

The properties of seven enzymes were studied in extracts from Myxobacter AL-1. The enzymes were isocitrate dehydrogenase (E.C.1.1.1.42), succinate dehydrogenase (E.C.1.3.99.1), alkaline phosphatase (E.C.3.1.3.1), alpha-glucosidase (E.C.3.2.1.20), beta-glucosidase (E.C.3.2.1.21), beta-galactosidase (E.C.3.2.1.23), and N-acetyl-glucosaminidase (E.C. 3.2.1.30). Four of these enzymes: isocitrate dehydrogenase, alpha-glucosidase, beta-glucosidase, and beta-galactosidase are cytosolic enzymes. Succinate dehydrogenase was found to be located on the cytoplasmic membrane system, whereas alkaline phosphatase and N-acetylglucosaminidase were considered as enzymes which bind the outer membranes resp. the cell wall. During the cell cycle, all enzymes have a pattern of discontinuous activity increase. Succinate dehydrogenase and isocitrate dehydrogenase exhibit a stepwise increase of activity, whereas the other enzymes follow the pattern of a peak enzyme.
 ...
PMID:Studies on the cell cycle of Myxobacter AL-1. II. Activities of seven enzymes during the cell cycle. 2 Aug 61

The regulation of lactate dehydrogenase in Bacillus subtilis was determined under a variety of growth conditions and in mutants blocked in the citric acid cycle. The synthesis of lactate dehydrogenase increased sharply concomitantly upon the exhaustion of glucose from the medium and the onset of the stationary phase. The synthesis of lactate dehydrogenase may be under catabolite repression control. Studies with mutants blocked in the citric acid cycle showed that lactate dehydrogenase is regulated independently of either the oxidative or reductase branches of the cycle. Certain citric acid cycle mutants, e.g., aconitase or succinate dehydrogenase, exhibited very low levels of lactate dehydrogenase while others, e.g., malate dehydrogenase or isocitrate dehydrogenase, showed normal levels. A stage O sporulation mutant expressed levels of lactate dehydrogenase more than one thousand-fold higher than the low group of citric acid cycle mutants. The induction of lactate dehydrogenase was shown to be independent of the accumulation of its substrate, pyruvate.
 ...
PMID:Regulation of lactate dehydrogenase synthesis in Bacillus subtilis. 10 66

The energy metabolism of cardiac hypertrophy in spontaneously hypertensive rats (SHR) was studied chronologically by histochemical and in part chemical methods. The activities of various enzymes, such as glucose-6-phosphate dehydrogenase (G6PDH), lactate dehydrogenase (LDH), isocitrate dehydrogenase, succinate dehydrogenase, beta-hydroxybutylate dehydrogenase (beta-HBDH) and monoamine oxidase (MAO) in the cardiac muscle were determined histochemically. beta-HBDH activity was greatly increased in the stage of developing hypertension in SHR. LDH activity increased simultaneously with the rise of beta-HBDH activity. Moreover, MAO activity increased markedly in later stages when the blood pressure was already elevated in SHR. To confirm the histochemical findings of beta-HBDH activity, the mitochondrial fraction of cardiac muscle was subjected to chemical assay. The chemical findings of myocardial beta-HBDH in SHR corresponded well with the histochemical findings. The myocardial beta-HBDH activity in SHR increased markedly at the age of 5 to 9 weeks, while no or minimal activity was found in controls of the same age. No significant difference of beta-HBDH activity was observed between SHR and controls in the mitochondrial fraction from the diaphragm and liver. The increase of beta-HBDH activity in the cardiac muscle of SHR prior to the development of cardiac hypertrophy suggests that the metabolism of ketone bodies may play an important role in providing the energy necessary for the development of cardiac hypertrophy in SHR.
 ...
PMID:Cardiac hypertrophy in spontaneously hypertensive rats. 12 86

During the ischemic shock caused by the removal of tourniquets placed on the hind paws of the rat, a marked decrease in the enzyme activities of Krebs cycle yielding ATP (malate dehydrogenase, isocitrate dehydrogenase, succinate dehydrogenase) at the level of the gastrocnemius muscle and the liver, was observed together with a plasma increase of these enzymes. The intraperitoneal injection of ATP diminishes significantly the variations observed.
 ...
PMID:[Variations of various enzymatic activities of the Krebs cycle (malate dehydrogenase, isocitrate dehydrogenase, succinate dehydrogenase) during experimental ischemic shock in the rat. Influence of adenosine 5' triphosphoric acid]. 13 5

Crossed immunoelectrophoresis of Triton X-100-solubilized plasma membranes of Micrococcus lysodeikticus established the presence of 27 discrete antigens. Individual antigens were identified as membrane components possessing enzyme activity by zymogram staining procedures and by reactivity of certain antigens with a selection of four lectins in the crossed-immunoelectrophoresis (immunoaffinoelectrophoresis) system. Absorption experiments with intact, stable protoplasts and isolated membranes established the asymmetric nature of the M. lysodeikticus plasma membranes. Of the 14 antigens with determinants accessible solely on the cytoplasmic face of the membrane, four possessed individual dehydrogenase activities, and a fifth was identifiable as a component possessing adenosine triphosphatase (EC 3.6.1.3) activity. Evidence from absorption studies with isolated membranes suggested that antigens such as the adenosine triphosphatase complex were more readily accessible to reaction with antibodies than was succinate dehydrogenase (EC 1.3.99.1), for example. Twelve antigens were located on the protoplast surface as determined by antibody absorption, and the succinylated lipomannan was identified as a major antigen. At least five other antigens possessed sugar residues that interacted with concanavalin A. With the antisera generated to isolated membranes, there was no evidence suggesting that any of these antigens was not detectable on either surface of the plasma membrane. From absorption experiments with washed, whole cells of M. lysodeikticus, it was concluded that the immunogens on the protoplast surface were also detectable on the surface of the intact cell. However, some of the components such as the succinylated lipomannan appeared to be exposed to a greater extent than others. The cytoplasmic fraction from M. lysodeikticus was used as an antigen source to generate antibodies, and 97 immunoprecipitates were resolvable by crossed immunoelectrophoresis. In the cytoplasm-anticytoplasm reference immunoelectrophoresis pattern of precipitates, three of the immunoprecipitates unique to the cytoplasmic fraction were identifiable by zymogram staining procedures as catalase (EC 1.11.1.6), isocitrate dehydrogenase (EC 1.1.1.42), and polynucleotide phosphorylase (EC 2.3.7.8). The identification of membrane and cytoplasmic antigens (including the above-mentioned enzymes) provides a sensitive analytical system for monitoring cross-contamination and antigen distribution in cellular fractions.
 ...
PMID:Membrane asymmetry and expression of cell surface antigens of Micrococcus lysodeikticus established by crossed immunoelectrophoresis. 14 22

Two groups of rats were provided simultaneously with a commercial stock diet for a period of 7 days. One group was fed ad libitum (control), and the other was restricted to one-fourth of the daily intake of control animals (semistarved). Body weight declined significantly in semistarved rats whereas body weight of controls increased over the 7-day period. The following were determined in vitro on mitochondria isolated from liver, kidney, and heart tissues of both groups: substrate-stimulated and DNP-uncoupled respiratory rates; specific acivities of the Krebs cycle dehydrogenases, and cytochrome c oxidase. Degradative effects of reduced food intake on mitochondrial function were observed. Uncoupled respiratory rates of liver and kidney mitochondria (using succinate as substrate) and heart mitochondria (using alpha-ketoglutarate and pyruvate) were lower. Also lower were activities of isocitrate dehydrogenase, NADP: isocitrate dehydrogenases, transhydrogenase, succinate dehydrogenase, and cytochrome c oxidase of heart mitochondria, transhdrogenase of liver mitochondria, and isocitrate dehydrogenase and transhydrogenase of kidney mitochondria. Such decreases in enzyme activities under conditions of dietary protein deficiency might have their basis in breakdown rates exceeding synthesis rates or result from partial inactivation of existing enzyme protein. Thus, there is evidence that responses to semistarvation of such parameters of mitochondrial function may differ among various tissues. In addition, liver and kidney citrate levels were lower and heart citrate level higher with semistarvation.
 ...
PMID:Effects of semistarvation on rat liver, kidney, and heart mitochondrial function. 16 2

A model of steady-state hypocitricemia, characterized by hypocitraturia and reduced kidney cortex citrate, has been demonstrated in the rate chronically exposed to environmental heat. The renal citrate extraction ratio remains unchanged. The physiological mechanism that brings about the reduction in circulating citrate has not been determined. Hypocitraturia likely results from a decreased filtered citrate load. Although it is generally contended that filtered citrate load. Although it is generally contended that alkalosis increases and acidosis decreases renal excretion of citrate, observations of mild alkalosis and hypocitraturia during heat exposure suggest that factors other than pH can alter renal handling of citrate. Kidney mitochondrial function, as determined by in vitro measurements of citrate-stimulated respiratory rates and specific activities of isocitrate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, and cytochrome c oxidase, appears to be unaffected by environmental heat.
 ...
PMID:RENAL HANDLING OF CITRATE DURING HEAT-INDUCED HYPOCITRICEMIA. 18 13

Oxidoreductases were studied histochemically in 162 cases of neuroectodermal tumors. In order of decreasing activity in the cytoplasma these enzymes could be arranged as follows: NADH diaphorase, lactate dehydrogenase, NADPH diaphorase, glutamate dehydrogenase, glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase, succinate dehydrogenase, malate dehydrogenase. The weak activity of Krebs cycle enzymes and the relatively strong activity of other oxidoreductases, particularly of lactate dehydrogenase, permits to conclude that glycolysis prevails over oxidative processes in neuroectodermal tumor cells. But this should not be interpreted as a decrease of the Krebs cycle enzymes in astrocytoma and oligodendroglioma cells as compared with their parent cells because the latter themselves display a weak activity of these enzymes. A real decrease of Krebs cycle enzyme activity was established only for tumors, the parent cells of which are characterized by a strong (in choroid-papillomas) or moderate (in ependymomas) activity of these enzymes. Many neuroectodermal tumors, in particular those of astrocytic origin, demonstrate a certain correlation between the amount of cytoplasm and oxidoreductase activity. This results in enzymatic polymorphism of the tumor tissue. A certain similarity was established of the oxidoreductase activity in tumor cells and in reactive hypertophic astrocytes. This indicates that both tumor cells and reactive astrocytes may in certain conditions utilize similar mechanisms of increased metabolism. The oxidoreductase activity correlates not with the grade of anaplasia but with different directions of anaplasia reflected in different variants of neuroectodermal tumors. The concept "anaplasia" includes not only certain degrees of dedifferentiation of tumor cells but, as it has been shown histochemically, also an increase of metabolic processes in the tumor cell cytoplasma.
 ...
PMID:Histochemistry of oxidoreductases, enzymatic polymorphism and anaplasia of neuroectodermal tumors. 18 68

Activity of pyruvate dehydrogenase (PDG), isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate dehydrogenase and malate dehydrogenase was found in the extracts of the cells of Bac. polymyxa 153, an organism producing polymyxin B. Dependence of the activity of the above enzymes on the carbon source in the medium, aeration conditions, strain features and culture age was shown. A low level of polymyxin B biosynthesis was observed at high activity of PDG and dehydrogenases of the tricarbonic acid cycle. Increased antibiotic production was recorded against the background of decreases values of the above enzyme activities.
 ...
PMID:[Polymyxin B biosynthesis and tricarboxylic acid cycle enzymatic activity]. 21 Jul 9


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