ABSTRACT
We investigate the longitudinal structure of the oxygen torus in the inner magnetosphere for a specific event found on 12 September 2017, using simultaneous observations from the Van Allen Probe B and Arase satellites. It is found that Probe B observed a clear enhancement in the average plasma mass (M) up to 3-4 amu at L = 3.3-3.6 and magnetic local time (MLT) = 9.0 h. In the afternoon sector at MLT ~ 16.0 h, both Probe B and Arase found no clear enhancements in M. This result suggests that the oxygen torus does not extend over all MLT but is skewed toward the dawn. Since a similar result has been reported for another event of the oxygen torus in a previous study, a crescent-shaped torus or a pinched torus centered around dawn may be a general feature of the O+ density enhancement in the inner magnetosphere. We newly find that an electromagnetic ion cyclotron (EMIC) wave in the H+ band appeared coincidently with the oxygen torus. From the lower cutoff frequency of the EMIC wave, the ion composition of the oxygen torus is estimated to be 80.6% H+, 3.4% He+, and 16.0% O+. According to the linearized dispersion relation for EMIC waves, both He+ and O+ ions inhibit EMIC wave growth and the stabilizing effect is stronger for He+ than O+. Therefore, when the H+ fraction or M is constant, the denser O+ ions are naturally accompanied by the more tenuous He+ ions, resulting in a weaker stabilizing effect (i.e., larger growth rate). From the Probe B observations, we find that the growth rate becomes larger in the oxygen torus than in the adjacent regions in the plasma trough and the plasmasphere.
ABSTRACT
Experiments were made on random-bred and linear mice, Wistar rats, rabbits and dogs to examine pharmacological properties of ubiquinone-9 and hexahydroubiquinone-4. Both compounds (oily solutions) administered intraperitoneally, intragastrically and subcutaneously in single and multiple doses produced no changes in the behavior or status of the animals, which might have attested to their toxicity. They were found to exert a regulatory action on the central nervous system, decreasing its sensitivity to numerous narcotic and convulsant substances without appreciable effects on the blood, arterial pressure, ECG and diuresis. The main obstacle for comprehensive experimental study and application of these substances in medical practice lies in the absence of a perfect medicinal form.
Subject(s)
Ubiquinone/analogs & derivatives , Ubiquinone/toxicity , Animals , Central Nervous System/drug effects , Dogs , Dose-Response Relationship, Drug , Electrocardiography , Male , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Rabbits , Rats , Rats, Inbred Strains , Time Factors , Ubiquinone/pharmacologyABSTRACT
It is shown that E-hypovitaminosis-induced muscular dystrophy in rabbits is accompanied by a sharp decrease in the body mass, an increase in the urine creatine-index, a decrease in the vitamin E and ubiquinone contents in the liver and skeletal muscle tissues. In the myocardium mitochondria a decrease in the vitamin E content and an increase in the ubiquinone content are observed. The activity of NADH-cytochrome c-, NADH-ubiquinone- and succinate-ubiquinone-reductase also varies in mitochondria of the studied tissues. In myocardium organellas a direct dependence is found between the content of ubiquinone, NADH- and succinate-ubiquinone-reductase activity and an inverse one-between its content and the activity of the NADH-cytochrome c-reductase system. It is established that p-oxybenzoic acid as well as vitamin E prevents development of muscular dystrophy and causes changes analogous in direction in the activity of the ubiquinone-dependent enzymic systems of mitochondria. Ubiquinone-9 is less efficient in preventing the development of muscular dystrophy.
Subject(s)
Muscular Dystrophy, Animal/prevention & control , Parabens/therapeutic use , Ubiquinone/therapeutic use , Vitamin E Deficiency/complications , Animals , Liver/metabolism , Mitochondria, Liver/enzymology , Mitochondria, Muscle/enzymology , Muscles/metabolism , Muscular Dystrophy, Animal/etiology , Muscular Dystrophy, Animal/metabolism , NADH, NADPH Oxidoreductases/metabolism , Rabbits , Ubiquinone/metabolism , Vitamin E/metabolismABSTRACT
It is shown that the activity of succinate- and NADH-ubiquinone-reductase systems as well as the ubiquinone content in the liver mitochondria of E-hypovitaminotic rats decrease as compared to their level in the liver mitochondria of healthy animals. Under conditions of E-hypovitaminosis alpha-tocopheronolactone and ubiquinone-9 3 h after intravenous injection to rats produce a pronounced normalizing effect on the ubiquinone content and on the activity of ubiquinone-dependent enzymic systems. It is assumed that a positive effect of vitamin E and its metabolite on the activity of these enzymic systems is to a considerable extent connected with an increase in the ubiquinone content in the rat liver mitochondria.
Subject(s)
Mitochondria, Liver/enzymology , Ubiquinone/metabolism , Vitamin E Deficiency/enzymology , Vitamin E/pharmacology , Animals , Electron Transport Complex II , Female , Kinetics , Mitochondria, Liver/drug effects , NAD(P)H Dehydrogenase (Quinone) , Oxidoreductases/metabolism , Quinone Reductases/metabolism , Rats , Succinate Dehydrogenase/metabolism , Succinates/metabolismABSTRACT
The paper deals with a review of the data available in literature on the regulation of the metabolic processes in microorganisms with CO2 fixation. The main function of CO2 is traced as exemplified by different types of microorganism nutrition. The carboxylation reactions in their main forms are observed in all heterotrophic microorganisms. The experimental data relative to the heterotrophic fixation of CO2 in yeast assimilating oil carbohydrates are presented as an example. The degree of CO2 fixation under these conditions may reach 30%. Carbon of CO2 is utilized for the biomass biosynthesis.
Subject(s)
Carbon Dioxide/metabolism , Carbohydrate Metabolism , Saccharomyces cerevisiae/metabolismABSTRACT
Using radioactive tracers, the effect of n-alkanes with a varying length--C16-C25--of the carbon chain on the rate of yeast growth and the ratio of major chemicals in their biomass was studied. The change in the level of n-alkanes accumulated by the yeast during carbon starvation was determined. No differences in the rate of metabolization of 1-14C-octadecane, 1,2-3H-hexadecane, and 13-14C-pentacosane were found. During 3 hour incubation the cell losses of C25, C18 and C16 amounted to 35.0, 33.0 and 38.1 microgram alkane/mg yeast, respectively. The intensity of yeast growth in the accumulative culture on dispersed n-alkanes with different molecular weights was similar. The specific formation of CO2 during the lag-phase by the yeast cultivated C18 was larger than on C23 or C25. The lipid content in the yeast grown on C18 was 3 times greater than in those grown on C22. The difference was made by an increased content of triglycerides and waxes.
Subject(s)
Alkanes/metabolism , Candida/metabolism , Candida/growth & development , Carbon Radioisotopes , Kinetics , Structure-Activity RelationshipABSTRACT
The effect of ubiquinones with different length of their chain (CoQ0, CoQ1, CoQ2, CoQ6, CoQ9) and their synthetic analogues (analogues of ubiquinone-1, hexahydroubiquinone-4, monophytylquinone, diphytylquinone, triphytylquinone) on the activity of ubiquinone dependent enzyme systems was studied in mitochondrial fractions from the yeast Candida guilliermondii. All of the ubiquinone homologues studied activated these systems. The synthetic analogues of ubiquinone nonspecifically inhibited the activity of NADH2-oxidase system. The inhibition was reversible when CoQ0 and CoQ1, but not CoQ6 and CoQ9, were added to the system. In the succinate-CoQ-reductase system, the inhibition caused by the analogues of ubiquinone was eliminated when all of the tested homologues were added to the system. In contrast to other analogues of ubiquinone, hexahydroubiquinone-4 was an inhibitor for the NADH2-oxidase system and an activator for the succinate-CoQ-reductase system, and eliminated the inhibiting action of other ubiquinone analogues in this system. Similar action of ubiquinone homologues was shown in the elimination of the inhibition of ubiquinone dependent systems caused by the specific inhibitors of electron transport, viz. rotenone and antimycin A.
Subject(s)
Candida/metabolism , Electron Transport , Ubiquinone/pharmacology , Antimycin A/pharmacology , Candida/drug effects , Mitochondria/drug effects , Multienzyme Complexes/metabolism , NADH, NADPH Oxidoreductases/metabolism , Oxidoreductases/metabolism , Rotenone/pharmacology , Succinate Dehydrogenase/metabolism , Ubiquinone/analogs & derivativesABSTRACT
The rates of growth, biomass accumulation, and electrophoretic spectra of mobile cytoplasmic proteins were studied with nonisogenous haploid and diploid cultures of Saccharomyces cerevisiae and Pichia guilliermondii as well as with isogenous haploid-diploid pairs of Saccharomyces cerevisiae and Pichia pinus. On a mineral medium with glucose, differences in these parameters in various yeast strains were found to be due to the genotype of a strain rather than to ploidy: nonisogenous haploid and diploid cultures displayed considerable and random variability of these properties while no differences were found in isogenous haploid-diploid pairs. Studies on solubility of protein fractions in various solvents made it possible to reveal differences connected with ploidy, namely: both in nonisogenous and isogenous haploid-diploid systems, the content of the water-soluble fraction decreased in diploid cultures.
Subject(s)
Ascomycota/analysis , Diploidy , Fungal Proteins/analysis , Haploidy , Pichia/analysis , Saccharomyces cerevisiae/analysis , Cytoplasm/analysis , DNA, Fungal/analysis , Electrophoresis, Polyacrylamide GelABSTRACT
The biosynthesis of lipids by Candida guilliermondii was studied during the growth of the yeast on carbon substrates which resulted in different pathways of lipid biosynthesis. The highest content of lipids was found during the growth on octadecane. The quantitative ratio between fractions of neutral lipids and phospholipids depended on the carbon substrate whereas the quanlitative composition of the fractions remained the same. The fatty acid composition of lipid fractions was studied, and possible pathways of their biosynthesis are discussed. Apparently, the assimilated hydrocarbon is oxidized to acetyl residues in certain structures of the yeast cells while, in other structures, the hydrocarbon substrate undergoes only monoterminal oxidation yielding an aliphatic alcohol and an acid which are directly used in large amounts for the synthesis of wax and triglycerides.
Subject(s)
Candida/metabolism , Lipids/biosynthesis , Acetates/metabolism , Alkanes/metabolism , Fatty Acids/biosynthesis , Phospholipids/biosynthesis , Yeasts/metabolismABSTRACT
Incorporation of 14C into various classes of lipids localized in the cell walls, large membranes, mitochondria and microsomes of yeast cells was studied during their incubation with 1-14C-octadecane. Cell structures were found to differ considerably by the kinetics and level of accumulation of 14C-components of the lipid fraction. Waxes and triglycerides prevail during primary accumulation of 14C-lipids in the large membranes and cell walls. Synthesis of these compounds is presumed to play an important role in the course of primary transformation of n-octadecane.
Subject(s)
Alkanes/metabolism , Candida/metabolism , Lipids/biosynthesis , Carbon Radioisotopes , Cell Membrane/metabolism , Cell Wall/metabolism , Microsomes/metabolism , Mitochondria/metabolism , Oxidation-Reduction , Triglycerides/biosynthesisABSTRACT
The activity of ubiquinone-dependent enzyme systems was studied in mitochondrial fractions of the yeast Candida guilliermondii cultivated on the medium containing carbohydrates of hydrocarbons as a source of carbon. The activity of NADH2-oxidase and succinate-CoQ-reductase was higher in systems with mitochondrial fractions from the cells grown on the medium with n-paraffins than in mitochondrial fractions from the cells cultivated on the medium with glucose. About 30% of intracellular ubiquinone is located in the mitochondrial fraction of hydrocarbon oxidizing yeast cells; however, the activity of enzymes was stimulated upon introduction of exogeneous ubiquinones into the systems. Therefore, exogeneous ubiquinones may be involved in the electron transport chain during oxidation of reduced substrates. Both ubiquinone-dependent enzyme systems are resistant to storage.
Subject(s)
Candida/metabolism , Ubiquinone/metabolism , Candida/enzymology , Electron Transport , Glucose/metabolism , Hydrocarbons/metabolism , Mitochondria/enzymology , NADH, NADPH Oxidoreductases/metabolism , Oxidation-Reduction , Succinate Dehydrogenase/metabolismABSTRACT
When n-alkane enters the cells as a result of molecular sorption and diffusion, it is distributed within all membrane structures of the cell (microsomes, mitochondria, membranes, vacuoles, cytoplasmic membranes, and cell walls). Sorption of n-alkane by all these structures in vivo comes at equilibrium after incubation of the cells with n-alkane during 3-4 min. Accumulation of the hydrocarbon in the morphological fractions of the cell depends on its concentration in the incubation medium. Isotherms of the sorption are convex curves. Sorption power, maximum sorption capacity, affinity and strength of the bonds with the hydrocarbon differ among the membrane structures of the cell. The maximum capacity of sorption of n-alkane by the structures does not correlate with the content of lipids and phospholipids in the structures. Sorption of n-alkanes is presumed to depend on the structural organization of lipids in the morphological fractions.
Subject(s)
Alkanes/metabolism , Yeasts/ultrastructure , Candida/metabolism , Candida/ultrastructure , Carbon Radioisotopes , Cell Fractionation , Cell Membrane/metabolism , Cell Wall/metabolism , Dose-Response Relationship, Drug , Kinetics , Microsomes/metabolism , Mitochondria/metabolism , Stearic Acids/metabolism , Structure-Activity Relationship , Yeasts/metabolismABSTRACT
Using the method of radioactive indicators, the specific content of proteins, lipids, total phosphorus, and lipid phosphorus was estimated in the morphological cell fractions of Candida tropicalis after growth in a liquid mineral medium containing n-octadecane as a source of carbon. The morphological cell fractions were produced by means of differential centrifuging. The following comparatively pure fractions were obtained simultaneously: soluble fraction, microsomes, mitochondria, large membranes, and cell walls.
Subject(s)
Candida/isolation & purification , Candida/analysis , Candida/cytology , Cell Fractionation , Cell Membrane/analysis , Cell Wall/analysis , Culture Media , Fungal Proteins/analysis , Lipids/analysis , Microsomes/analysis , Mitochondria/analysis , Phosphorus/analysisABSTRACT
Six strains of Candida guillermondii of different productivity showed a higher isocitrate lyase and malate dehydrogenase activity of cell-free extracts when grown on paraffin than when grown on glucose. In most cases isocitrate dehydrogenase activity was higher on glucose than on paraffin. A positive correlation between isocitrate activity and growth rate was found from studies of the strains of varying growth rate and the cultures cultivated under different conditions (nitrogen content and the presence or absence of biotin or autolysate in the medium).