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PubMed1991

Succinate stimulation of isocitrate supported deoxycorticosterone metabolism in rat adrenal mitochondria by a synergistic mechanism.

The relative effectiveness of succinate and isocitrate in supplying NADPH for cholesterol and deoxycorticosterone (DOC) metabolism by rat adrenal mitochondria has been investigated. As previously seen for cholesterol metabolism, isocitrate supported DOC metabolism at a higher rate than succinate. Maximal rates of DOC metabolism, however, required 10 times more precursor (10mM) than cholesterol metabolism. Addition of DOC to mitochondria inhibited cholesterol metabolism, indicating competition for NADPH between these pathways. Coaddition of these reducing precursors resulted in a substantially greater than additive rate of DOC hydroxylation, but not cholesterol metabolism. The synergistic effect was seen with both 11 beta- and 18 hydroxylation. For both precursors, the synergism was maximal upon addition of only 1 mM of the second precursor. The synergistic effect was far more resistant to added KCN and malonate than succinate supported DOC metabolism, and neither inhibitor affected isocitrate supported DOC metabolism. These results suggest that while cytochromes P450scc and P450(11 beta) use a common supply of NADPH generated by each precursor, there is a pool of NADPH that is only effectively synthesised upon coaddition of precursors and only utilised by cytochrome P450(11 beta). This second NADPH pool may be produced in response to potentiated isocitrate dehydrogenase activity or activation of a different NADPH generating system.

Adrenal Glands↗
PubMed1981

[Protein supply of rats and transaminase and succinate dehydrogenase activity].

The influence of an isocaloric diet containing 13 and 20% of crude protein on the activities of GOT, GPT and succinic dehydrogenase in rat livers was determined and compared to the growth as well as to the body composition of the animals. The weights of the animals were significantly increased, feed efficiency and consumption of metabolizable energy per gram of body increase were much better with higher protein supply. It may be concluded that protein retention was better while fat retention was nearly unaffected. The activities of the liver enzymes increased with the protein content of the diet, especially GOT 1,8 times and succinic dehydrogenase 3 times as compared to the respective values of the lower protein group. It is discussed that the activity of succinic dehydrogenase represents a suitable criterion for the evaluation of a changed metabolism, especially when protein supply is marginal.

Alanine Transaminase↗
PubMed1976

Hepatic organelle interaction. IV. Mechanism of succinate enhancement of formaldehyde accumulation from endoplasmic reticulum N-dealkylations.

Further evidence for organelle interaction during drug metabolism by the liver is presented. The apparent stimulation by succinate of formaldehyde accumulation in the medium, which was reported to occur with liver slices and homogenates as well as with mitochondria plus microsomes, has been shown to be the result of succinate inhibition of mitochondrial aldehyde dehydrogenase. The mechanism of succinate inhibition is shown to be by reverse electron transport, and an increase in the NADH to NAD+ ratio in the mitochondria; the aldehyde dehydrogenase requires the oxidized form of the pyridine nucleotide as its cofactor. Studies on in vitro N-demethylation by liver microsomes and endoplasmic reticulum segments which cosediment with the mitochondria indicate that formaldehyde produced by the mixed function oxidase is handled differently from formaldehyde added to the medium. The latter is mainly retained in the medium containing 5 mM semicarbazide, while the generated formaldehyde is more than 50% consumed by the mitochondria. Electron microscopy has indicated that the microsomes and the endoplasmic reticulum fragments have a tendency to align themselves close to the mitochondria when present in the same medium. Consequently, it is possible that formaldehyde released to the medium adjacent to the mitochondria, as by N-demethylation, would be exposed to semicarbazide for shorter periods than that added directly to the medium. In agreement with this suggestion, complexing of formaldehyde with semicarbazide was observed spectroscopically not to be an extremely rapid reaction even at 37 degrees C. This is believed to be the reason for the greater extent of consumption of formaldehyde generated by the endoplasmic reticulum.

Aldehyde Oxidoreductases↗
PubMed1953

Effect of infection with M. tuberculosis and of tuberculin shock on the succinic dehydrogenase activity of guinea pig tissues.

The kidney of guinea pigs infected with the H37Rv and BCG strains of M. tuberculosis showed a diminution in succinic dehydrogenase activity when measured by the tetrazolium technique. This effect was also seen in the liver and spleen of animals infected with the BCG strain. Sensitized animals showed similar results when given tuberculin in sublethal doses. The succinic oxidase was also low in the kidneys of animals infected with the H37Rv strain. The depressed enzyme activity of the tissues of infected animals could be restored to normal by addition of normal tissue extract or dialysate. This suggests that the alteration in tissue metabolism observed in tuberculosis may depend upon the loss of some as yet unidentified factor important for succinic dehydrogenase activity.

Animals↗
PubMed1978

Starvation and refeeding in rats: effect on organismic respiration, cytoplasmic constituents of liver, and succinic dehydrogenase activity in liver, kidney, and heart.

An analysis of starvation and starvation followed by refeeding was undertaken to characterize some organismic, organ, and mitochondrial responses to these two circumstances. Body weight, organismic respiration as well as weight protein and succinic dehydrogenase activity for liver, kidney, and heart were determined over the course of 6 days of starvation and 5 days refeeding for adult male rats. Assays of marker enzyme activities for mitochondria (cytochrome oxidase), lysosomes (acid phosphatase), endoplasmic reticulum (glucose-6-phosphatase), and plasma membranes (5'-nucleotidase) were conducted for liver in addition to quantitations of mitochondrial protein. All enzyme determinations were done on whole tissue homogenates and reported as total organ activity. Liver mitochondria were harvested quantitatively directly from whole liver homogenates by zonal centrifugation for determination of mitochondrial protein. Starvation resulted in a major loss of body weight, organ weight, and organ protein; liver greater than kidney greater than heart. These changes were accompanied by a major reduction in organ succinic dehydrogenase activity; liver greater than kidney. In heart, succinic dehydrogenase was doubled in activity at day 2 of starvation and subsequently diminished to values not significantly lower than controls. In liver, mitochondrial mass (protein) was severely diminished. From analysis of marker enzyme activities, it appeared that lysosomes, endoplasmic reticulum, and plasma membrane were also decreased. Refeeding restored the greatest part of these losses within 5 days.

Animals↗
PubMed1983

Characterization of a pleiotropic succinate dehydrogenase-negative mutant of Bacillus subtilis.

A succinate dehydrogenase-negative mutant of Bacillus subtilis is described which lacks all three subunits of the membrane-bound succinate dehydrogenase complex: flavoprotein, iron protein, and cytochrome b558. The corresponding mutation is revertible and it maps at one extreme of the sdh region. The results presented suggest that the structural genes for the subunits of the succinate dehydrogenase complex are part of one operon.

Bacillus subtilis↗
PubMed2003

Berberine formate-succinic acid (1/1).

The title compound [systematic name: 9,10-dimethoxy-2,3-methylenedioxy-5,6-dihydrodibenzo[a,g]quinolizinium formate-succinic acid (1/1)], C(20)H(18)NO(4)(+).CHO(2)(-).C(4)H(6)O(4), contains centrosymmetric pairs of almost planar berberine cations, and hydrogen-bonded (C(4)H(6)O(4).HCOO(-))(2) rings of succinic acid with formate anions, bonded by O-H...O hydrogen bonds with O...O distances of 2.4886 (15) and 2.5652 (16) A. Pairs of cations and molecules of succinic acid are connected by non-conventional weak C-H.O hydrogen bonds, with C...O distances of 3.082 (2) and 3.178 (2) A.

Berberine↗
PubMed2006

Succinic semialdehyde couples stress response to quorum-sensing signal decay in Agrobacterium tumefaciens.

Quorum sensing (QS) signal decay in Agrobacterium tumefaciens occurs in response to starvation or host signals. We have demonstrated that the gamma-aminobutyric acid (GABA) shunt metabolite links stress response to QS signal decay. Mutation of the aldH gene encoding a succinic semialdehyde dehydrogenase (SSADH) that converts succinic semialdehyde (SSA) to succinic acid results in early expression of the signal degrading enzyme, AttM. Exogenous addition of SSA or its precursor GABA induces AttM expression and abolishes Ti plasmid conjugative transfer. SSA acts by binding to the repressor AttJ that regulates the attKLM operon. attK encodes another SSADH. The stress alarmone ppGpp and SSA modulates separately the expression of the two SSADH enzymes, which might control the intracellular SSA level and hence to switch on/off the QS signal decay system in response to environmental changes. These findings document for the first time a sophisticated signalling mechanism of the widely conserved GABA degradation pathway in prokaryotes.

Agrobacterium tumefaciens↗
PubMed1978

The effects of long-term therapy with oestriol succinate on the haemostatic mechanism in postmenopausal women.

In a previous report we showed that oestriol succinate administered to postmenopausal women caused fewer changes in haemostatic function over a four-month period than ethinyloestradiol. Potential longer-term effects were studied in postmenopausal women treated for osteoporosis with oestriol succinate for up to 12 months. Over this period there was no significant change in concentration of plasma coagulation factors, an increase in plasminogen concentration and euglobulin lysis activity, and an inconsistent increase in platelet sensitivity to aggregation induced by ADP and collagen. The relative lack of effect of oestriol succinate on coagulation function is encouraging with regard to the future incidence of thromboembolic complications of therapy.

Adult↗
PubMed1985

Identification of pig brain aldehyde reductases with the high-Km aldehyde reductase, the low-Km aldehyde reductase and aldose reductase, carbonyl reductase, and succinic semialdehyde reductase.

Four NADPH-dependent aldehyde reductases (ALRs) isolated from pig brain have been characterized with respect to substrate specificity, inhibition by drugs, and immunological criteria. The major enzyme, ALR1, is identical in these respects with the high-Km aldehyde reductase, glucuronate reductase, and tissue-specific, e.g., pig kidney aldehyde reductase. A second enzyme, ALR2, is identical with the low-Km aldehyde reductase and aldose reductase. The third enzyme, ALR3, is carbonyl reductase and has several features in common with prostaglandin-9-ketoreductase and xenobiotic ketoreductase. The fourth enzyme, unlike the other three which are monomeric, is a dimeric succinic semialdehyde reductase. All four of these enzymes are capable of reducing aldehydes derived from the biogenic amines. However, from a consideration of their substrate specificities and the relevant Km and Vmax values, it is likely that it is ALR2 which plays a primary role in biogenic aldehyde metabolism. Both ALR1 and ALR2 may be involved in the reduction of isocorticosteroids. Despite its capacity to reduce ketones, ALR3 is primarily an aldehyde reductase, but clues as to its physiological role in brain cannot be discerned from its substrate specificity. The capacity of succinic semialdehyde reductase to reduce succinic semialdehyde better than any other substrate shows that this reductase is aptly named and suggests that its primary role is the maintenance in brain of physiological levels of gamma-hydroxybutyrate.

Alcohol Oxidoreductases↗
PubMed1989

Human brain glyceraldehyde-3-phosphate dehydrogenase, succinic semialdehyde dehydrogenase and aldehyde dehydrogenase isozymes: substrate specificity and sensitivity to disulfiram.

Several enzymes active in the presence of NAD with acetaldehyde and propionaldehyde have been purified from human brain and characterized. The enzymes have been identified as aldehyde dehydrogenase (EC 1.2.1.3), NAD-linked succinic semialdehyde dehydrogenase (EC 1.2.1.24), and glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12). Glyceraldehyde-3-phosphate dehydrogenase is extremely heterogeneous with some isozymes active with acetaldehyde, others inactive. The cytoplasmic enzyme, which is the classical glyceraldehyde-3-phosphate dehydrogenase, is inactive with acetaldehyde as substrate; the isozymes that are active with short chain aliphatic aldehydes are localized in the mitochondrial fraction. Properties of glyceraldehyde-3-phosphate dehydrogenase isozymes with respect to short chain aliphatic aldehydes and inhibition by disulfiram are described. Their Km values for acetaldehyde range from 300 to 2000 microM. All glyceraldehyde-3-phosphate dehydrogenases that are active with acetaldehyde are easily inactivated by low concentrations of disulfiram. In all cases activity regain can be obtained with 2-mercaptoethanol; in the case of two glyceraldehyde-3-phosphate isozymes (E8.5 and 9.0), activity can also be regained with cysteine and with glutathione; activity of E6.6 and E6.8 glyceraldehyde-3-phosphate dehydrogenases could not be regained with 33 microM cysteine or glutathione. Succinic semialdehyde dehydrogenase and aldehyde dehydrogenase (EC 1.2.1.3) were also inhibited by disulfiram; their activity could be regained with 2-mercaptoethanol but not with 33 microM cysteine or glutathione. Comparison of human brain succinic semialdehyde dehydrogenase and aldehyde dehydrogenase with glyceraldehyde-3-phosphate dehydrogenase shows that the activity with short chain aldehydes is not unique to aldehyde dehydrogenase; neither is sensitivity to disulfiram; activity with 3,4-dihydroxyphenylacetaldehyde appears to be a unique property of aldehyde dehydrogenase (EC 1.2.1.3).

Aldehyde Dehydrogenase↗
PubMed1999

Biochemical and molecular characterization of a succinate semialdehyde dehydrogenase involved in the catabolism of 4-hydroxybutyric acid in Ralstonia eutropha.

A succinate semialdehyde dehydrogenase gene (gabD) was identified to be disrupted in a transposon-induced mutant of Ralstonia eutropha exhibiting the phenotype 4-hydroxybutyric acid-leaky. The native gabD gene was cloned by colony hybridization using a homologous gabD-specific DNA probe. DNA sequencing revealed an 1452-bp open reading frame, and the deduced amino acid sequence showed strong similarities to NADP(+)-dependent succinate semialdehyde dehydrogenases from Escherichia coli, Rhizobium sp., Homo sapiens and Rattus norvegicus. The gabD gene was heterologously expressed in a recombinant E. coli strain harboring plasmid pSK::EE6.8. Similar to the molecular organization of the gab cluster in E. coli, additional genes encoding enzymes for the degradation of gamma-aminobutyrate are closely related to gabD in R. eutropha. Enzymatic studies indicated the existence of a second NAD(+)-dependent succinate semialdehyde dehydrogenase in R. eutropha.

Aldehyde Oxidoreductases↗
PubMed1976

Liver and heart mitochondrial succinate dehydrogenase activity of newborn rats in anoxic hypoxia and starvation.

Succinate dehydrogenase activity was determined in the liver and heart of newborn rats after 3 and 48 hours' exposure to anoxic hypoxia (10% O2) and after 48 hours' starvation. Control determinations were made on newborn animals of corresponding ages, full term foetuses (21 days), infantile (1 and 2 weeks) and full grown animals. Hypoxia for 3 h had no influence on succinate dehydrogenase activity at all in either the heart or liver mitochondria of the newborn animals. After 48 h no difference was observed in the liver between the hypoxic animals and the starved controls of the same age, though starvation itself had resulted in a significant increase in activity, as much as 42%. When liver mitochondrial succinate dehydrogenase in normal mitochondria was activated by preincubation mitochondria with the substrate, the activity increase obtained was greater than that resulting from starvation. The increase in activity in the heart of the hypoxic or starved animals was not significant (less than 10%).

Age Factors↗
PubMed1991

Resistance to fatigue of single muscle fibres from Xenopus related to succinate dehydrogenase and myofibrillar ATPase activities.

This report describes how the resistance to fatigue of a muscle fibre relates to the fibre's most important ATP-producing and ATP-consuming reactions. Twelve intact single muscle fibres were dissected from lumbrical muscles of Xenopus laevis. Their resistance to fatigue induced by repeated tetanic stimulation was determined, as well as their succinate dehydrogenase activity and calcium-stimulated myofibrillar ATPase activity. The enzyme activities were determined by means of quantitative histochemistry. It was found that resistance to fatigue correlates with succinate dehydrogenase activity (r = 0.83) and with myofibrillar ATPase activity (r = -0.74). The highest correlation was found between resistance to fatigue and the ratio of succinate dehydrogenase to myofibrillar ATPase activity (r = 0.93). It is concluded that muscular fatigue is closely related to cellular energetics.

Adenosine Triphosphatases↗
PubMed2004

Effect of overexpression of Actinobacillus succinogenes phosphoenolpyruvate carboxykinase on succinate production in Escherichia coli.

Succinate fermentation was investigated in Escherichia coli strains overexpressing Actinobacillus succinogenes phosphoenolpyruvate carboxykinase (PEPCK). In E. coli K-12, PEPCK overexpression had no effect on succinate fermentation. In contrast, in the phosphoenolpyruvate carboxylase mutant E. coli strain K-12 ppc::kan, PEPCK overexpression increased succinate production 6.5-fold.

Actinobacillus↗
PubMed1973

Factors affecting virulence of Shigella flexneri: avirulent strain with altered metablism of succinate, fumarate, and malate.

It has been found that a mutation of Shigella flexneri 2a to avirulence can result in altered metabolism of tricarboxylic acid cycle acids, but the effect is strongly dependent on growth conditions. Mutant cells harvested from stationary-phase cultures grown with vigorous shaking in nutrient broth oxidize succinate, fumarate, and malate much more slowly than do wild-type cells. Cell-free extracts from such cells show similar differences in oxidative ability. These differences were less pronounced when cells were harvested from the exponential phase of growth and were nonexistent when the cells were grown without shaking. When tricarboxylic acid cycle acids were used as carbon sources with shaking, mutant cells from exponential phase cultures oxidized tricarboxylic cycle acids almost to the same extent as the wild type. Stationary-phase cells grown on succinate lost succinoxidase activity, but wild-type cells retained more than twice the activity of mutant cells. The effect of growth conditions on oxidative differences between the two strains was similar to the differences in succinate uptake observed under similar conditions.

Azides↗
PubMed1971

Characterization of the membrane-bound succinic dehydrogenase of Micrococcus lysodeikticus.

The occurrence of succinic dehydrogenase [succinic:(acceptor) oxidoreductase, EC 1.3.99.1] in membrane fractions of Micrococcus lysodeikticus was investigated. The enzyme could be purified 10-fold, by deoxycholate treatment. Butanol extraction of membranes yielded an active fraction, nonsedimentable at 130,000 x g for 2 hr and altered in its phospholipid content relative to membranes. The activity of the enzyme in particulate preparations was decreased in the presence of competitive inhibitors and by compounds known to react with iron, sulfhydryl groups, and flavine. In this respect, the bacterial succinic dehydrogenase is similar to the enzyme derived from yeast and mammalian sources. In certain membrane fractions, Ca(2+) and Mg(2+) exhibited inhibitory effects whereas Triton X-100 caused activation. The enzyme could also be activated by substrate. In the phenazine reductase assay, incomplete reduction of electron acceptor was observed upon addition of divalent cations and iron binding agents.

Alcohols↗
PubMed1988

Mutants of Rhizobium meliloti defective in succinate metabolism.

We characterized mutants of Rhizobium meliloti SU47 that were unable to grow on succinate as the carbon source. The mutants fell into five groups based on complementation of the succinate mutations by individual recombinant plasmids isolated from a R. meliloti clone bank. Enzyme analysis showed that mutants in the following groups lacked the indicated common enzyme activities: group II, enolase (Eno); group III, phosphoenolpyruvate carboxykinase (Pck); group IV, glyceraldehyde-3-phosphate dehydrogenase (Gap), and 3-phosphoglycerate kinase (Pgk). Mutants in groups I and V lacked C4-dicarboxylate transport (Dct-) activity. Wild-type cells grown on succinate as the carbon source had high Pck activity, whereas no Pck activity was detected in cells that were grown on glucose as the carbon source. It was found that in free-living cells, Pck is required for the synthesis of phosphoenolpyruvate during gluconeogenesis. In addition, the enzymes of the lower half of the Embden-Meyerhoff-Parnas pathway were absolutely required for gluconeogenesis. Eno, Gap, Pck, and one of the Dct loci (ntrA) mapped to different regions of the chromosome; the other Dct locus was tightly linked to a previously mapped thi locus, which was located on the megaplasmid pRmeSU47b.

Chromosome Mapping↗