Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Succinates”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 811 records · Page 45Linked to original sources
PubMed1975

Cross-linking of Escherichia coli succinic thiokinase. I. Reaction with diiminoesters and dimaleimides.

Treatment of the tetrameric alpha2 beta2 protein succinic thiokinase of Escherichia coli with dimethylsuberimidate (DMS) yielded five protein species detectable by sodium dodecyl sulfate polyacrylamide gel electrophoresis. These five protein species had estimated molecular weight values of 29,500, 41,000, 73,000, 117,000, and 132,000, and corresponded to alpha monomer, beta monomer, alpha beta dimer, alpha2 beta trimer and alpha2 beta2 tetramer, respectively. In all cases, the cross-linking produced predominantly the 73,000 molecular weight dimer with respectively lesser amounts of the tetramer and trimer. Succinic thiokinase was also cross-linked by reaction with N, N'-o-phynylenedimaleimide or with N, N'-P-phenylenedimaleimide. In these instances, treatment produced the alpha beta dimer as the only oligomeric species. Ammonolysis of isolated tetramer, trimer, and dimer produced by DMS treatment gave the 29,500 molecular weight monomer (alpha monomer) and the 38,500 molecular weight monomer (beta monomer). The absence of dimers of like subunits and the predominance of the dimer of unlike subunits are consistent with a quaternary structure of the native enzyme in which unlike subunits are closely associated but like subunits are not. Under certain conditions, an additional dimer of approximately 60,000 molecular weight was produced. This appeared to result from cleavage of the beta chain of an alpha beta dimer. Phosphorylation of native succinic thiokinase with [gamma-32P]ATP and [gamma-32P]GTP showed radioactivity only in the alpha monomer. Phosphorylation of enzyme before or after cross-linking showed radioactivity in all cross-linked bands except the beta monomer. Experiments in which the enzyme was titrated with [14C]DMS and trinitrobenzenesulfonate revealed that approximately half of the available amino groups reacted with the diiminoester, but that a small fraction of these (smaller than 20%) had reacted bifunctionally

Adenosine Triphosphate↗
PubMed1975

[Effect of a mixed E. coli O-111 (RNA-azopositive and RNA-azonegative strains) and Coxsackie B3 viral infection on oxygen demand and on the succinate dehydrogenase activity of an HEp-2 cell culture according to polarographic study data].

The authors determined polarographically the intensity of oxygen consumption and the activity of succinic dehydrogenase of the HEp-2 cell culture infected with the association of the Cocksackie B3 with the RNA-asopositive and RNA-asonegative strains of E. coli O--111, in comparison with the uninfected and separately infected virus or control bacteria. The results were recorded 2, 6, 12, 18 and 24 hours after the infection of the cell cultures. Mixed virus-bacterial infection intensified the oxygen consumption and the activity of succinic dehydrogenase by the HEp-2 cells, followed by a profound respiratory depression. The same effect was produced by the infection of cells by the virus alone. Less pronounced was the action of bacterial component. A change in the cell repiration of the infected cultures was independent of the RNA-ase activity of bacteria. Under conditions of mixed infection the intensity of the changes in oxygen consumption and of the succinic dehydrogenase activity was determined by the viral component of the association.

Carcinoma, Squamous Cell↗
PubMed1975

Regulation of succinic dehydrogenase activity of heart mitochondria by anti-arrhythmic drugs.

It was observed that either propranolol or iproveratril could increase the succinate oxidation activity by rat heart mitochondria to 444% and to 371% respectively. Both drugs decreased the respiratory control coefficient and ADP/O ratio. No effect on mitochondrial succinic dehydrogenase, succinic dehydrogenase-Co Q-reductase and malic dehydrogenase was observed. It was pointed out that these drugs would act preventing the reoxidation of NADH+ + H+ through the respiratory chain.

Amino Acids↗
PubMed1975

[Studies on the distribution of glycogen phosphorylase and succinate dehydrogenase in the humeral epiphysis of various-age rats].

In the chondrocytes of the humerus epiphysis of newborn and 8-, 30- and 60-day-old albino rats, glycogen phosphorylase and succinate dehydrogenase activity was found. The enzymatic pattern of glycogen phosphorylase and succinate dehydrogenase diverges significantly within the age groups. In the chondrocytes of cartilage epiphysis of newborn and 8-day-old animals glycogen phosphorylase is distinctly present. The enzyme is reduced in 30- and 60-day-old rats. The initial moderate reactions of succinate dehydrogenase in the column cartilage and in the proximal hypertrophic cells demonstrate an additional activity from 30-day-old animals. The osteoblasts of the metaphysis demonstrated a strong reaction.

Age Factors↗
PubMed2001

[Pathomorphology of regenerative processes in mandibular fracture after sodium succinate treatment and laser magnetotherapy in an experimental setting].

Morphological reactions in tissue adjacent to mandibular angular fracture were studied in guinea pigs treated with sodium succinate and laser magnetotherapy. Due to succinate therapy the exudative component of inflammation was less expressed in comparison with the control, macrophagal reaction and neoangiogenesis were activated, the volume of damaged muscle tissue and the incidence of suppurations decreased. The number of osteoblasts increased and new bone structures acquired a lamellar pattern earlier than in the control. Sodium succinate therapy in combination with laser magnetotherapy had a more pronounced positive effect as regards activation of macrophagal reaction and neoangiogenesis and a decrease in the area of fibrosclerotic changes in the zone of damaged muscles, where newly formed myosymplasts differentiated into myotubes and even in muscle fibers. Suppuration of the wound was prevented. Bone tissue in the fracture zone formed without preliminary formation of cartilaginous tissue, which resulted in more rapid osteogenesis (lamellar bone growth in the fracture zone).

Animals↗
PubMed1992

Succinate-DCPIP and NADH-fumarate oxidoreductases in fresh water snails susceptible and non susceptible to schistosoma infection.

The activities of succinate-DCPIP oxidoreductase (SO) and NADH-fumarate oxidoreductase (FR) were determined in tissue homogenate of Biomphalaria alexandrina and Bulinus truncatus, the snail vectors of Schistosomiasia. A parallel study was done on Lymnea truncatula snails which are not susceptible to Schistosoma infection. The Michaelis constant (Km) and maximum velocities (Vmax) for fumarate reduction and succinate oxidation by the tissue homogenates from the three species were determined. The results obtained showed that both susceptible species are aerobic and lactate is the sole end product of anaerobic glycolysis. Lymnea truncatula snails are facultative anaerobic producing succinate as a major end product in the glycolytic pathway.

Animals↗
PubMed1991

Protein-ubiquinone interaction in bovine heart mitochondrial succinate-cytochrome c reductase. Synthesis and biological properties of fluorine substituted ubiquinone derivatives.

To investigate the protein-ubiquinone interaction in the bovine heart mitochondrial succinate-cytochrome c reductase region of the respiratory chain, three fluorine substituted ubiquinone derivatives, 2,3-dimethoxy-6-(9'-fluorodecyl)-1,4-benzoquinone (9FQ), 2-methoxy-5-trifluoromethyl-6-decyl-1,4-benzoquinone (TFQ), and 2-methoxy-5-trifluoromethyl-6-(9'-fluorodecyl)-1,4-benzoquinone (9FTFQ), were synthesized. 9FQ was synthesized by radical coupling of Q0 and bis(10-fluoroundecanoyl)peroxide. The latter was prepared by fluorination of undecylenic acid followed by thionylchloride treatment and peroxidation. TFQ was synthesized from 2,2,2-trifluoro-p-cresol by methylation, nitration, reduction, acetylation, nitration, reduction, oxidation, and radical alkylation. 9FTFQ was prepared by the radical alkylation of 2-methoxy-5-trifluoromethyl-1,4-benzoquinone with bis(10-fluoroundecanoyl)peroxide. All three fluoro-Q derivatives are active (greater than 50% the activity of 2,3-dimethoxy-5-methyl-6-decyl-1,4-benzoquinone) when used as electron acceptors for succinate-ubiquinone reductase. However, only 9FQ is active when used as an electron donor for ubiquinol-cytochrome c reductase or as an electron mediator for succinate-cytochrome c reductase. Both TFQ and 9FTFQ are competitive inhibitors for ubiquinol-cytochrome c reductase. A 19FNMR peak-broadening effect was observed for 9FQ when it was reconstituted with ubiquinone-depleted ubiquinol-cytochrome c reductase. A drastic up-field chemical shift was observed for TFQ when it was reconstituted with ubiquinone-depleted reductase. These results indicate that the binding environments of the benzoquinone ring and the alkyl side chain of the Q molecule are different. The strong up-field chemical shift for TFQ, and lack of significant chemical shift for 9FQ, suggest that the benzoquinone ring is bound near the paramagnetic cytochrome b heme.

Animals↗
PubMed1976

Thermodynamic and EPR characteristics of a HiPIP-type iron-sulfur center in the succinate dehydrogenase of the respiratory chain.

In addition to the two species of ferredoxin-type iron-sulfur centers (Centers S-1 and S-2), a third iron-sulfur center (Center S-3), which is paramagnetic in the oxidezed state analogous to the bacterial high potential iron-sulfur protein, has bwen detected in the reconstitutively active soluble succinate dehydrogenase preparation. Midpoint potential (at pH 7.4) of Center S-3 determined in a particulate succinate-cytochrome c reductase is +60 +/- 15 mV. In soluble form, Center S-3 becomes extremely labile towards oxygen or ferricyanide plus phenazine methosulfate similar to reconstitutive activity of the dehydrogenase. Thus, even freshly prepared reconstitutively active enzyme preparations show EPR spectra of Center S-3 which correspond approximately to 0.5 eq per flavin; in particulate preparations this component was found in a 1:1 ratio to flavin. All reconstitutively inactive dehydrogenase preparations that Center S-3 is an innate constituent of succinate dehydrogenase and plays an important role in mediating electrons from the flavoprotein subunit to most probably ubiquinone and then to the cytochrome chain.

Animals↗
PubMedDate not supplied

[Effect of methylguanidine and guanidine succinic acid on methemoglobin reductase activity in human red cells].

Activity of methemoglobin reductase was studied in human red cells treated with methylguanidine and guanidinosuccinic acid in concentrations similar to those in plasma of patients with chronic renal failure. Enzyme activity was measured with Richterich technique following an incubation at 37 degrees C for three hours. Results have shown that methylguanidine in concentration of 5.4 x 10(-5) mol/l decreases activity of methemoglobin reductase in human red cells on average by 13.9%. Higher concentrations potentiate this effect. Similar changes in methemoglobin reductase activity were noted after introduction of guanidine-succinic acid into the mixture. This agent in concentration 5.6 x 10(-5) mol/l inhibited activity of the tested enzyme by 34.2% on average. Combined methylguanidine in concentration of 5.4 x 10(-5) mol/l and guanidine-succinic acid in concentration of 2.8 x 10(-5) mol/l inhibited methemoglobin reductase activity by 33.0% on average. It may be suggested, that methylguanidine and guanidine-succinic acid being low molecular uremic toxins may significantly decrease methemoglobin reductase activity in red cells of patients with chronic renal failure.

Adult↗
PubMed1979

Succinic semialdehyde dehydrogenase. Reactivity of lysyl residues.

The enzyme succinic semialdehyde dehydrogenase from pig brain has been 2000-fold purified by a combination of DEAE-cellulose, hydroxyapatite, and AMP-Sepharose chromatography. This preparation has a molecular weight of 160,000 and a specific activity of 5.3 mumol/min.mg at 25 degrees C. The inhibition of succinic semialdehyde dehydrogenase by carbonyl compounds, i.e. P-pyridoxal and o-phthalaldehyde was investigated in detail. The enzyme is reversible, inhibited by preincubation with P-pyridoxal (mixing molar ratio, 300:1) at either 25 degrees or 37 degrees C. Reduction with NaBH1 results in the incorporation of approximately 4 mol of P-pyridoxyl residues/mol of enzyme. NAD+ protects the enzyme against inactivation by P-pyridoxal, whereas the substrate succinic semialdehyde failed to prevent the reaction of P-pyridoxal with lysine residues of the protein. The binding of approximately 10 mol of o-phthalaldehyde/mol of enzyme results in irreversible loss of catalytic activity. The reaction is fast and easily monitored by absorption and fluorescence spectroscopy.

Aldehyde Oxidoreductases↗
PubMed1989

A quantitative histochemical study of delta 5-3 beta-hydroxysteroid dehydrogenase and succinate dehydrogenase activities in the bovine corpus luteum of pregnancy.

In corpora lutea of pregnancy of dairy cows delta 5-3 beta-hydroxysteroid dehydrogenase and succinate dehydrogenase were demonstrated histochemically and evaluated densitometrically. Serum progesterone was determined radioimmunologically. Activities per volume unit of delta 5-3 beta-hydroxysteroid dehydrogenase and succinate dehydrogenase in large and small luteal cells as well as progesterone concentrations, exhibited no typical and correlated pattern during pregnancy. Large luteal cells in regressive tissue regions showed weaker delta 5-3 beta-hydroxysteroid dehydrogenase activities than in maturing or well-developed tissue regions. Succinate dehydrogenase activities of small luteal cells were highest in regressive luteal tissue. The results indicate that structural development of bovine luteal tissue during pregnancy is reflected by corresponding enzyme activities.

3-Hydroxysteroid Dehydrogenases↗
PubMed1986

[Succinate oxidation by rat brain mitochondria in experimental convulsions].

Corasole-induced convulsive fits are accompanied by the activation of succinate oxidation in the isolated mitochondria, paralleled by the mounting effect of factors limiting succinate dehydrogenase activity. Diverse seasonal sensitivity to corasole correlates with the inhibition of succinate-dependent energy supply for the functional neuronal activity.

Animals↗
PubMed1979

[Two sites of ubisemiquinone binding in mitochondrial succinate oxidase].

The inhibiting effects of several phenol compounds on electron transfer in the respiratory chain of submitochondrial particles were studied. It was shown that the terminal part of the succinate dehydrogenase complex contains a site, which specifically binds the negatively charged phenols (e. g. pentachlorophenol, 2,4-dibromophenol, 2-methoxy-4,6-dibromophenol). The efficiency of the inhibitor anion binding by this site is increased 12-fold after introduction of a methoxy-group into the o-position of 2,4-dibromophenol. Since this site binds both methoxy- and negatively charged phenol groups, it can also act as a possible site of ubisemiquinone interaction with succinate dehydrogenase. Based on the structural similiarity of the b-c1 complex inhibitors, e. g. antimycin, o-hydroxybenzoic acid amides, 2-hydroxy-3-alkyl-1,4-quinones, and ubisemiquinone, an assumption has been made on possible ubisemiquinone binding between cytochromes b and c1. A structural analysis of phenols inhibiting succinate dehydrogenase and the b-c1 complex revealed that in the region between cytochromes b and c1 there act only the inhimitors which contain: a) a negatively charged phenol group; b) a group comprising a heteroatom with an undepleted electron pair and which can act as a ligand, and c) a hydrophobic residue.

Animals↗
PubMedDate not supplied

[Succinate dehydrogenase localization in the mitochondria of the renal tubules of cold- and warm-blooded vertebrates].

Using electron microscopic histochemical technique, studies have been made on the activity of succinic dehydrogenase in the kidneys of the cod Gadus morrhua and dog. It was shown that chelate granules indicating localization of the enzyme in the mitochondria of nephronal cells, concentrate mainly in two zones -- between the membranes and inside the cristae. This distribution of the enzyme implies the presence of two pools of succinic dehydrogenase in the mitochondria which are utilized at different stages of oxidative phosphorylation. Succinic dehydrogenase content of the cristae is lower in cod than in dog.

Animals↗
PubMed1984

Hematoporphyrin derivative-induced photosensitivity of mitochondrial succinate dehydrogenase and selected cytosolic enzymes of R3230AC mammary adenocarcinomas of rats.

The photosensitizing activity of hematoporphyrin derivative (HPD) was investigated by studying selected enzymes localized to mitochondria and cytosol of R3230AC mammary adenocarcinomas. Experiments in vitro demonstrated that mitochondrial succinate dehydrogenase was inhibited in a drug dose- and light exposure time-related manner; at 7.0 micrograms of HPD per ml or higher, enzyme activity was inhibited greater than 50% after 15 min of photoradiation. The three cytosol enzymes studied under the same conditions in vitro demonstrated different photosensitivities. Pyruvate kinase activity was significantly inhibited in a dose- and time-related fashion, whereas lactate dehydrogenase was inhibited to a lesser extent, and glucose phosphate isomerase activity was inhibited only at the highest dose (70 micrograms of HPD per ml) used. The time-course of these responses was examined with an in vivo-in vitro protocol, consisting of photoradiation of mitochondria and cytosol prepared from tumors obtained at various times (up to 1 week) after a single injection of HPD (80 mg/kg). Pyruvate kinase activity was markedly inhibited at early times returning to initial levels by 48 hr; neither lactate dehydrogenase nor glucose phosphate isomerase was inhibited by this treatment. Mitochondrial succinate dehydrogenase and cytochrome c oxidase activities displayed significant photoradiation-induced inhibitions, with greatest inhibition occurring between 24 and 96 hr after injection of HPD; at 1 week, succinate dehydrogenase activity had returned to its initial level, but cytochrome c oxidase activity remained significantly inhibited. These data suggest that HPD-induced photosensitization of mitochondria may be an important site of action contributing to tumor cell cytotoxicity and regression as a result of photoradiation therapy.

Adenocarcinoma↗
PubMed1981

Thermodynamic and electron paramagnetic resonance characterization of flavin in succinate dehydrogenase.

Thermodynamic parameters of succinate dehydrogenase flavin were determined potentiometrically from the analysis of free radical signal levels as a function of the oxidation-reduction potential. Midpoint redox potentials of consecutive 1-electron transfer steps are -127 and -31 mV at pH 7.0. This corresponds to a stability constant of intermediate stability, 2.5 x 10(-2), which suggests flavin itself may be a converter from n = 2 to n = 1 electron transfer steps. The pK values of the free radical (FlH . in equilibrium Fl . -) and the fully reduced form (FlH2 in equilibrium FlH-) were estimated as 8.0 +/- 0.2 and 7.7 +/- 0.2, respectively. Succinate dehydrogenase flavosemiquinone elicits an EPR spectrum at g = 2.00 with a peak to peak width of 1.2 mT even in the protonated form, suggesting the delocalization in the unpaired electron density. A close proximity of succinate dehydrogenase flavin and iron-sulfur cluster S-1 was demonstrated based on the enhancement of flavin spin relaxation by Center S-1.

Anaerobiosis↗
PubMedDate not supplied

Dicyclohexylcarbodiimide inhibition of succinate- and ubiquinol-cytochrome c reductase in beef heart mitochondria.

We have found that dicyclohexylcarbodiimide (DCCD) inhibits both the succinate-cytochrome c and the ubiquinol-cytochrome c reductases in cytochrome c-depleted mitochondria. On the other hand the succinate-ubiquinone reductase is not decreased at the same levels of the inhibitor. The inhibition curve of DCCD results sigmoidal for succinate-cytochrome c reductase, whereas it is hyperbolic for the ubiquinol-1-cytochrome c reductase, with also a lower apparent KI. The inhibition appears dependent both on the time of preincubation and on the mitochondrial concentration. The apparent Km for ubiquinol-1 is increased and the maximal velocity of ubiquinol-cytochrome c reductase is decreased by DCCD. The effects do not appear to be caused by unspecific modification of the physicochemical state of the bc1 region of the respiratory chain. The results therefore suggest the presence of a DCCD-sensitive electron transfer step in the redox pathways from ubiquinol to cytochrome c.

Animals↗