Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.6.3.14 (ATP synthase)
7,042 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The fatty acid composition of the ole-1 and ole-1 petite mutants of Saccharomyces cerevisiae was manipulated by growing the organism in the presence of defined supplements of Tween 80 or by allowing cells that had first been grown in the presence of Tween 80 to deplete their unsaturated fatty acids by sequent growth in the absence of Tween 80. 2. The transition temperature of Arrhenius plots of mitochondrial ATPase (adenosine triphosphatase) increases as the unsaturated fatty acid content is lowered. 3. Cells require larger amounts of unsaturated fatty acids to grow on ethanol at lower temperatures. 4. Cells that stop growing owing to unsaturated fatty acid depletion at low temperatures are induced to grow further by raising the temperature and this results in a further depletion of unsaturated acids. This is due to a higher rate, but not a greater efficiency, of mitochondrial ATP synthesis. 5. Arrhenius plots of the passive permeability of mitochondria to protons between 4 and 37 degrees C are linear. The rate and the Arrhenius activation energy of proton entry increase greatly as the unsaturated fatty acid content is lowered. 6. Unsaturated fatty acid depletion has the same effects on the proton permeability of ole-1 petite mitochondria, indicating that the mitochondrially synthesized subunits of the ATPase are not involved in the enhanced rates of proton entry. 7. The adenylate energy charge of depleted ole-1 cells is greatly decreased by growth on ethanol medium. 8. The adenylate energy charge of isolated mitochondria is also lowered by unsaturated fatty acid depletion. 9. The results confirm that unsaturated fatty acid depletion uncouples oxidative phosphorylation in yeast both in vivo and in vitro, and is a consequence of changes in the lipid part of the membrane.
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PMID:The effects of unsaturated fatty acid depletion on the proton permeability and energetic functions of yeast mitochondria. 14 59

An attempt has been made to determine the location of the site at which the metabolism of ethanol interacts with that of choline to produce an increase in the oxidation of choline. The first enzyme in the oxidation pathway for choline, choline dehydrogenase, was assayed using a newly developed spectrophotometric assay and freshly isolated intact rat liver mitochondria. No changes were observed in either 'apparent' V or the 'apparent' Km values of choline dehydrogenase for choline after ethanol ingestion. However, when the choline oxidase system was assayed, a 28% decrease in 'apparent' Km for choline and a 53% increase in 'apparent' V was observed. The effects of ATP on choline oxidase were studied further, and a 29.4% decrease was observed in mitochondrial ATP levels from freshly isolated mitochondria from the ethanol-treated rats. In vitro aging of mitochondria further decreased the level of ATP, and the rate of decrease was considerably faster during the first hour in the mitochondria from the ethanol-treated animals. The decreases in ATP from both control and experimental mitochondria were accompanied by increases in choline oxidase activity. The initial decrease in ATP was correlated with an increase in mitochondrial ATPase activity which may be related to an increase in mitochondria Mg2+. Because chronic ethanol ingestion has resulted in decreased oxidation rates of succinate and beta-hydroxybutyrate while at the same time increasing the oxidation rates of choline, the studies reported here suggest that the effect of chronic ethanol ingestion is primarily on a step that is unique to choline and which probably exists prior to the electron transport chain.
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PMID:A possible mechanism for the increased oxidation of choline after chronic ethanol ingestion. 15 26

Studies have been made on ATPase from chloroplasts, cyanobacteria and mitochondria of higher plants and animals. No intraspecies and interspecies variability of chloroplast and mitochondrial ATPase was found with respect to pH optimum of the activity, to specificity to cations as substrate components, to sensitivity to stimulating and inhibiting anions and ethanol, to optimal stimulating ethanol concentration. Intergenus variation of these properties of ATPase from chloroplasts, plant mitochondria, and cyanobacteria was revealed. Analysis of homology of the amino acid sequence in ATP-synthase subunits showed that ATP-synthase genes in chloroplast DNA originate from cyanobacterial genome, whereas ATP-synthase genes in plant and animal mitochondria-from genome of Rhodospirillum rubrum or closely related species. It was established that no recombination between the genetic material of chloroplasts and mitochondria took place during evolution.
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PMID:[The evolutionary changes in the amino acid sequences and properties of the ATP-synthase in chloroplasts, mitochondria and bacteria]. 144 93

This study concerns the assembly into a multisubunit enzyme complex of a small hydrophobic protein imported into isolated mitochondria. Subunit 8 of yeast mitochondrial ATPase (normally a mitochondrial gene product) was expressed in vitro as a chimaeric precursor N9L/Y8-1, which includes an N-terminal-cleavable transit peptide to direct its import into mitochondria. Assembly into the enzyme complex of the imported subunit 8 was monitored by immunoadsorption using an immobilized anti-F1-beta monoclonal antibody. Preliminary experiments showed that N9L/Y8-1 imported into normal rho+ mitochondria, with its complement of fully assembled ATPase, did not lead to an appreciable assembly of the exogenous subunit 8. With the expectation that mitochondria previously depleted of subunit 8 could allow such assembly in vitro, target mitochondria were prepared from genetically modified yeast cells in which synthesis of subunit 8 was specifically blocked. Initially, mitochondria were prepared from strain M31, a mit- mutant completely incapable of intramitochondrial biosynthesis of subunit 8. These mit- mitochondria however were unsuitable for assembly studies because they could not import protein in vitro. A controlled depletion strategy was then evolved. An artificial nuclear gene encoding N9L/Y8-1 was brought under the control of a inducible promoter GAL1. This regulated gene construct, in a low copy number yeast expression vector, was introduced into strain M31 to generate strain YGL-1. Galactose control of the expression of N9L/Y8-1 was demonstrated by the ability of strain YGL-1 to grow vigorously on galactose as a carbon source, and by the inability to utilize ethanol alone for prolonged periods of growth. The measurement of bioenergetic parameters in mitochondria from YGL-1 cells experimentally depleted of subunit 8, by transferring growing cells from galactose to ethanol, was consistent with the presence in mitochondria of a mosaic of ATPase, namely fully assembled functional ATPase complexes and partially assembled complexes with defective F0 sectors. These mitochondria demonstrated very efficient import of N9L/Y8-1 and readily incorporated the imported processed subunit 8 protein into ATPase. Comparison of the kinetics of import and assembly of subunit 8 showed that assembly was noticeably delayed with respect to import. These findings open the way to a new systematic analysis of the assembly of imported proteins into multisubunit mitochondrial enzyme complexes.
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PMID:Assembly of imported subunit 8 into the ATP synthase complex of isolated yeast mitochondria. 213 40

The F1 portion of H(+)-translocating ATPase as purified from membrane vesicles of Vibrio parahaemolyticus by a rapid procedure. The whole purification process (from culture of cells to purification of the enzyme) could be completed in 1 day. The F1-ATPase consists of five subunits (alpha, beta, gamma, delta and epsilon) like F1 of Escherichia coli and other microorganisms. The F1-ATPase of V. parahaemolyticus showed some interesting properties. Its activity was greatly stimulated by high concentrations (about 0.5 M) of SO4(2-), SO3(2-) and CH3COO-, their effects decreasing in this order. Among the anions tested, Cl- and NO3- were ineffective, or rather inhibitory, and cations had no significant effects. Ethanol (or methanol) stimulated the activity 2- to 3-fold. The activity was inhibited by 4-acetamido-4'-isothiocyanostilbene 2,2'-disulfonate (SITS) (an anion exchanger inhibitor), tetrachlorosalicylanilide (TCS) (an H+ conductor), azide and N-ethylmaleimide. Zinc inhibited the activity only slightly, although it strongly inhibited the ATPase activity in membrane vesicles.
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PMID:Rapid purification and characterization of F1-ATPase of Vibrio parahaemolyticus. 214 93

Several mutants of yeast lacking the porin gene have been found stable and viable on glucose or glycerol media. Ethanol-supported respiration of porin-free mutant and wild cells appeared equally coupled in vivo being similarly depressed by inhibitors of ADP/ATP translocase or of ATP synthase and stimulated by the uncoupler FCCP. The absence of porin in isolated mutant mitochondria hardly impaired the electron flux but increased the requirement for Mg2+ (or Ca2+) and for ADP and carboxyatractylate concentrations necessary to drive effectively state 3 - state 4 and state 4 - state 3 transitions, respectively. The existence of another porin species, possibly controlled by bivalent cations, is postulated.
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PMID:The respiration of cells and mitochondria of porin deficient yeast mutants is coupled. 216 77

An inhibitor of Crithidia fasciculata and Trypanosoma cruzi H+ -ATP synthase (ATPase) was isolated from these organims mitochondrial particles, either by (a) ammonium sulfate-cholate extraction followed by heat treatment and ethanol precipitation, or (b) gel-filtration on Sephadex G-50, followed by a similar purification procedure. Inactivation by trypsin supported the inhibitor peptide structure. Removal of the peptide inhibitor increased about three-fold the specific activity of the protozoan ATPases. The isolated peptides and a highly purified bovine heart ATPase inhibitor inhibited C. fasciculata ATPase as a function of the peptide concentration.
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PMID:Isolation of the peptide inhibitor of H+-ATP synthase from Crithidia fasciculata and Trypanosoma cruzi. 252 3

The association of an ATPase with the yeast peroxisomal membrane was established by both biochemical and cytochemical procedures. Peroxisomes were purified from protoplast homogenates of the methanol-grown yeast Hansenula polymorpha by differential and sucrose gradient centrifugation. Biochemical analysis revealed that ATPase activity was associated with the peroxisomal peak fractions which were identified on the basis of alcohol oxidase and catalase activity. The properties of this ATPase closely resembled those of the mitochondrial ATPase of this yeast. The enzyme was Mg2+-dependent, had a pH optimum of approximately 8.5 and was sensitive to N,N'-dicyclohexylcarbodiimide (DCCD), oligomycin and azide, but not to vanadate. A major difference was the apparent Km for ATP which was 4-6 mM for the peroxisomal ATPase compared to 0.6-0.9 mM for the mitochondrial enzyme. Cytochemical experiments indicated that the peroxisomal ATPase was associated with the membranes surrounding these organelles. After incubations with CeCl3 and ATP specific reaction products were localized on the peroxisomal membrane, both when unfixed isolated peroxisomes or formaldehyde-fixed protoplasts were used. This staining was strictly ATP-dependent; in controls performed in the absence of substrate, in the presence of glycerol 2-phosphate instead of ATP, or in the presence of DCCD, staining was invariably absent. Similar staining patterns were observed in subcellular fractions and protoplasts of Candida utilis and Trichosporon cutaneum X4, grown in the presence of ethanol/ethylamine or ethylamine, respectively.
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PMID:A proton-translocating adenosine triphosphatase is associated with the peroxisomal membrane of yeasts. 288 51

Liver mitochondria from rats fed ethanol chronically demonstrated a 35% decrease in mitochondrial ATPase activity. Moreover, the ATPase activity was inhibited only 61% by addition of oligomycin. Treatment of mitochondria from ethanol-fed rats with the detergent, Lubrol-WX, caused the release of 36% of the F1 from the resulting inner membrane particles. In comparison, only 5% of the F1 was dissociated when control mitochondria were subjected to the Lubrol treatment. However, when the units of ATPase activity from the supernatant and particles obtained after Lubrol treatment were added together, their sums were equivalent in preparations from control and ethanol-fed animals. Moreover, polyacrylamide gel electrophoresis analyses indicated equal amounts of the alpha + beta subunits of F1 in mitochondria from control and ethanol-fed rats. Reconstitution experiments with urea particles and F1 prepared from both control and ethanol mitochondria revealed a decrease in oligomycin sensitivity which could be attributed to an alteration in the functioning of either the oligomycin sensitivity conferring protein or a membrane sector subunit that interacts with oligomycin. Analysis by reconstitution also demonstrated that there were no ethanol-elicited alterations in the properties of the F1 portion of the ATP synthase complex. These observations indicate that the activity of the ATP synthase complex is altered significantly by ethanol-elicited changes in the functioning of those polypeptides involved in modulating both oligomycin sensitivity and the association of F1 with membrane sector subunits.
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PMID:Ethanol-elicited alterations in the oligomycin sensitivity and structural stability of the mitochondrial F0 . F1 ATPase. 288 57

The conformations of the H+-ATPase complex and F1-ATPase in low concentrations of methanol, ethanol, n-propanol, iso-propanol and t-butanol were studied by circular dichroism. For F1-ATPase, all but methanol first increased and then decreased the circular dichroism magnitude of helical bands as the alcohol concentration was increased. With ethanol, n-propanol, iso-propanol and t-butanol, the alpha-helix content reached a maximum at about 5% alcohol and began to decrease at 10%. The content of beta-sheet showed the opposite effect, reaching a minimum at 5% and increasing slightly at higher concentrations. None of the alcohols studied had a significant effect on the conformation of the H+-ATPase complex. This difference implies that the alcohols had a greater effect on free F1-ATPase than on the membrane-bound F1-ATPase. The hydrophobic protein F0 and the membrane lipids in the H+-ATPase complex may stabilize and protect F1 from the effects of the alcohols.
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PMID:Effects of some alcohols on the conformation of mitochondrial H+-ATPase complex and F1-ATPase from pig heart. 288 69


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