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)

Tightly bound adenine nucleotides are removed from multiple binding sites on beef heart mitochondrial ATPase (F1) by chromatography on columns of Sephadex equilibrated with 50% glycerol. Release of nucleotides from the enzyme is associated with large decreases in sedimentation velocity (from 11.9 S to 8.4 S) which may be observed in concentrated solutions of polyols. Polyol-induced conformational changes are reversed when the enzyme is returned to dilute buffers. The nucleotide-depleted enzyme restores oxidative phosphorylation in F1-deficient submitochondrial particles. Reconstitution of nucleotide-depleted F1 with the ATP analog (adenylyl-imidodiphosphate (AMP-PNP), almost 5 moles of AMP-PNP per mole of enzyme, results in preparations with substantially inhibited ATPase activity which nevertheless restores oxidative phosphorylation and the 32Pi-ATP exchange reaction in F1-deficient submitochondrial particles. Incubation of the analog-labeled enzyme with ATP and Mg++ results in partial displacement of the analog and a time-dependent recovery of ATPase activity.
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PMID:Physical and enzymatic properties of nucleotide-depleted beef heart mitochondrial adenosine triphosphatase. 12 61

Effect of respiration toxins is studied on some properties of mitochondrial membranes and functions connected with ion transport for the expence of ATP energy. The combination of three respiration inhibitors (cyanide, antimycin and rotenone) was shown to develope the following effects: 1) the inhibition of K+ accumulation by mitochondria at the presence of ATP and valinomycin; 2) the decrease in acidification of non-mitochondrial space, accompanying to the K+ transport; 3) the activation of latent mitochondrial ATPase; 4) the inhibition of DNP-stimulated ATPase; 5) the inhibition of mitochondria swelling, caused by K+, Ca2+, or dimethyldibenzylammonium (DDA+) at the presence of ATP+phopshate (or acetate); 6) the stimulation of passive mitochondria swelling in 0.1 MNH4NO3; 7) the inhibition of ATP-induced contraction of mitochondria, swelling in NH4NO3. The data obtained are discussed in a wiev of the conception, which suggests that the attaching of inhibitors to respiration enzymes changes the configuration of the latters, thus disturbing natural structural bond of these enzymes with other protein components of the membrane. The latter can result in the impair of electroisolating membrane properties, in the increase of its conductivity for H+ and other ions, and in the decrease of Vm values of some enzymatic reaction, which are not directly connected with the respiration chain (such as ATPase reaction).
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PMID:[Respiration toxins as inhibitors of ion transport, supported by ATP hydrolysis, in mitochondria]. 12 71

The isolation and characterisation of a mutant affecting the assembly of mitochondrial ATPase is reported. The mutation confers resistance to oligomycin and venturicidin and sensitivity of growth on nonfermentable substrates to low temperature (19degrees). Genetic analysis indicates that the phenotype is due to a single mutation located on the mitochondrial DNA which is probably allelic with the independently isolated oligomycin resistance mutation [oli1-r]. Growth of the mutant at the non-restrictive temperature (28degrees) yields mitochondria in which the ATPase appears more sensitive to oligomycin than that of the sensitive parental strain. However, when the enzyme is isolated free from the influence of the membrane strong resistance to oligomycin is evident. These data suggest that the component responsible for the oligomycin resistance of the ATPase is part of or subject to interaction with the mitochondrial inner membrane. Measurements of the ATPase content of mitochondria indicate that ATPase production is impaired during growth at 19degreesC. In addition, studies of the maximum inhibition of mitochondrial ATPase activity by high concentrations of oligomycin suggest a selective lesion in ATPase assembly at low temperature. The nett result is that during growth at 19degrees only about 10% of the normal level of ATPase is produced of which less than half is membrane integrated and thus capable of oxidative energy production. We propose that the mutation affects a mitochondrially synthesised membrane sector peptide of the ATPase which defines the interaction of F1ATPase with specific environments on the mitochondrial inner membrane.
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PMID:Biogenesis of mitochondria 36, The genetic and biochemical analysis of a mitochondrially determined cold sensitive oligomycin resistant mutant of Saccharomyces cerevisiae with affected mitochondrial ATPase assembly. 12 72

A bean chloroplast coupling factor (CF1) with latent Ca2+-dependent ATPase activity was studied. Immunodiffusion of bean (Phaseolus vulgaris) chloroplast and etioplast coupling factors and spinach coupling factor against antiserum to spinach coupling factor showed partial identity of the bean coupling factor with that of spinach. An immunoelectrophoretic comparison, under dissociating conditions, of bean leaf extracts and spinach extracts containing CF1 subunits (as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis) gave identical results for both extracts. At least six distinct polypeptide species were found. The major species had molecular weights of 42 000, 59 000 and 63 000 daltons. Amino acid analysis of electrophoretically purified bean CF1 gave results similar to those published for spinach CF1.
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PMID:Subunit studies of coupling factor 1 of bean chloroplasts. 13 66

Preparation of surface membranes from mouse L-cells using a technique previously described in the literature [Perdue & Sneider, 1970] allowed characterization of a Ca-activated ATPase apparently separate from the mitochondrial ATPase also dependent on calcium. This enzyme is associated with the Na-K-ATPase, a marker for surface membranes, and not wilth alkaline phosphatase, a mitochondrial enzyme. In temperature sensitivity, pH dependence and inhibition by ethacrynic acid, the partially purified enzyme has properties similar to those previously described for active calcium efflux from these cells. For maximal activity of the enzyme system magnesium and sodium are required, although the calcium transport from whole cells was apparently independent of both. Adenosine triphosphate only was metabolized by the enzyme system, whereas CTP could be utilized for calcium transport from 'ghost' cells, probably as a result of intracellular conversion to ATP. It is suggested that the active calcium transport from cultured L-cells is closely linked to the calcium dependent ATPase, and that the method of calcium extrusion is similar to that described for red blood cells.
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PMID:Properties of the calcium-activated adenosine tri-phosphatase from L-cell membranes. 13 77

Several classes of anti-inflammatory agents including acetyl-salicylic acid, salicylic acid, flufenamic acid, phenyl-butazone, indometacin, oxyphenyl-butazone, and mefenamic acid were found to be inhibitors of rat liver mitochondrial ATPase in both intact and freeze-ruptured mitochondria. The freeze-ruptured mitochondrial ATPase was found to be Mg2+- and ATP-concentration dependent. The standard uncoupler, 2,4-dinitrophenol, not possessing anti-inflammatory activity, activates the enzyme in both preparations. A number of compounds of various structural classes possessing no anti-inflammatory property in vivo were found to have no inhibitory effect on the enzyme. This inhibition of ATPase by anti-inflammatory agents could be used as an in vitro test method for the primary screening of potential anti-inflammatory agents.
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PMID:Influence of anti-inflammatory agents on rat liver mitochondrial ATPase. 13 89

A preparation of soluble mitochondrial ATPase (coupling factor F1) containing no gamma and delta minor subunits has been isolated. The minor-subunits-deficient F1 was found to be competent in ATP hydrolysis. However, it did not demonstrate a "coupling" effect in EDTA-submitochondrial particles. A portion of the ATPase activity of EDTA particles, stimulated by the minor-subunits-deficient F1, was insensitive to oligomycin. ATPase activity of Na+-particles was changed only slightly by this F1. It is suggested that gamma and delta subunits are necessary to form specific contacts between the F1 molecule and components of the mitochrondrial membrane.
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PMID:Functional role of soluble mitochondrial ATPase subunits. 13 32

Different mitochondrial mutants have been isolated that affect mitochondrial ribosome function. These mutants were used to establish most of the known methods and principles of mitochondrial genetics in yeast. Another class of mitochondrial mutants have been shown to affect mitochondrial ATPase and, more specifically, the "membrane factor" of mitochondrial ATPase. These mutants might be very useful in studying the energy-conserving function, and the interaction between the hydrophobic and hydrophylic parts, of the ATPase complex. New types of mitochondrial point mutations, concerning cytochrome a-a3 or b, will soon open up new fields of investigation. The biochemical and genetic analysis of numerous mutants belonging to that category and recently obtained [31] is being currently pursued in Tzagoloff's and Slonimski's laboratories.
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PMID:Genetic analysis of mitochondrial biogenesis and function in Saccharomyces cerevisiae. 13 34

Soluble mitochondrial ATPase (F1) from beef heart prepared in this laboratory contained approximately 1.8 mol of ADP and 0 mol of ATP/mol of F1 which were not removed by repeated precipitation of the enzyme with ammonium sulfate solution or by gel filtration in low ionic strength buffer containing EDTA. This enzyme had full coupling activity. Treatment of the enzyme with trypsin (5 mug/mg of F1 for 3 min) reduced the "tightly bound" ADP to zero, abolished coupling activity, but had no effect on the ATPase activity, stability, or membrane-binding capability of the F1. When the trypsin concentration was varied between 0 and 5 mug/mg of F1, tightly bound ADP was removed to varying degrees, and a correlation was seen between amount of residual tightly bound ADP and residual coupling activity. Gel filtration of the native F1 in high ionic strength buffer containing EDTA also caused complete loss of tightly bound ADP and coupling ability, whereas ATPase activity, stability, and membrane-binding capability were retained. The ADP-depleted F1 preparations were unable to rebind normal amounts of ADP or any ATP in simple reloading experiments. The results strongly suggest that tightly bound ADP is required for ATP synthesis and for energy-coupled ATP hydrolysis on F1. The results also suggest that ATP synthesis and energy-linked ATP hydrolysis rather than involving one nucleotide binding site on F1, involve a series or "cluster" of sites. The ATP hydrolysis site may represent one component of this cluster. The results show that nonenergy-coupled ATP hydrolysis on F1 can occur in the absence of tightly bound ADP or ATP.
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PMID:Removal of "tightly bound" nucleotides from soluble mitochondrial adenosine triphosphatase (F1). 13 45

In rats treated with single, sublethal doses of p,p'-DDT oxidative phosphorylation efficiency, respiratory activity and "latent" ATPase activity in liver and brain mitochondria were determined. A time- and dose-dependent decrease in oxidative phosphorylation efficiency was found. Time-dependent suppression of respiratory activity in state 3 was noticed and a stimulation of mitochondrial ATPase activity 24 h after DDT treatment in liver and brain mitochondria was found. The correlation between time-dependent changes in the brain mitochondrial fraction and distribution of DDT in brain after a single, oral dose is discussed. It is suggested that changes in mitochondria were caused by DDT and its metabolites. It is concluded that the uncoupling of oxidative phosphorylation especially in brain mitochondria could be responsible for some DDT intoxication symptoms in mammals.
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PMID:The mode of action of p,p'=DDT on mammalian mitochondria. 13 71


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