PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “ADENOSINE TRIPHOSPHATASE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 181 records · Page 10Linked to original sources
PubMed1978

Isolation of Escherichia coli mutants with an adenosine triphosphatase insensitive to aurovertin.

Energy-transducing adenosine triphosphatase (ATPase) from Escherichia coli is inhibited by aurovertin. Aurovertin-resistant mutants were generated by nitrosoguanidine mutagenesis of E. coli AN180, whose growth on a nonfermentable carbon source was blocked by aurovertin. The ATPase activity of cell extracts from 15 different mutants (designated MA1, MA2, MA3, etc.) was found to be at least 20 times less sensitive to aurovertin than that from the parent strain. The aurovertin-resistant mutants did not show cross-resistance towards a number of ATPase inhibitors including azide, dicyclohexylcarbodiimide, quercetin, 7-chloro-4-nitrobenzofurazan, and N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline. Aurovertin inhibited the energization brought about by addition of ATP to E. coli AN180 membrane vesicles; it was without effect on MA1 and MA2 membrane vesicles energized by ATP. The mutation in MA1, like other mutations of the ATPase complex, maps in the unc region of the bacterial chromosome.

Adenosine Triphosphatases↗
PubMed1969

Interaction of a bacterial adenosine triphosphatase with phospholipid bilayers.

A solubilized nonparticulate adenosine triphosphatase from Streptococcus fecalis spheroplast membranes (Abrams, A., and C. Baron, Biochemistry, 7,501 (1968)) interacts at pH 7.5 with lipid bilayer membranes to produce a 10(2)- to 10(4)-fold increase in the electric conductance of the bilayer. In addition, a small decrease in the electrical capacitance of the interactant system is also observed. Interaction is obtained with bilayers formed from a solution in n-decane of either purified egg phosphatidyl-choline, synthetic diphytanoyl phosphatidyl-choline, or a total extract of the membrane lipid of S. fecalis. The magnitude of the increase in conductance is dependent on the presence of Mg(++) and upon the concentrations of both Na(+) and K(+) in the range of 10(-2) to 10(-1)M. An additional tenfold increase in conductance is obtained when ATP is added to the ambient aqueous phase surrounding the bilayer ATPase interactant system. No conductance change is obtained with ATPase which has been treated with pronase. ATPase activity is dependent upon Mg(++) and upon the concentrations of Na(+) and K(+) in the region of 10(-1)M. The function of the ATPase in the intact bacterial membrane is apparently associated with the active transport of cations. The increased conductance in the bilayer which results from its interaction with the ATPase, together with the similarity between the dependence of this interaction and the dependence of ATPase activity on Mg(++), ATP, and the Na(+), K(+) concentrations suggests that the bilayer-ATPase interactant complex may be similar in structure and properties to the membrane-ATPase complex in the intact organism.

Adenosine Triphosphatases↗
PubMed1968

Comparison of some minor activities accompanying a preparation of sodium-plus-potassium ion-stimulated adenosine triphosphatase from pig brain.

1. An ATPase (adenosine triphosphatase) preparation obtained from pig brain microsomes by treatment with sodium iodide showed four apparently different ouabain-sensitive activities under various conditions. They were (a) ouabain-sensitive Mg(2+)-stimulated ATPase, (b) K(+)-stimulated ATPase, (c) (Na(+),K(+))-stimulated ATPase and (d) Na(+)-stimulated ATPase activities. 2. These activities showed the same substrate specificity, ATP being preferentially hydrolysed and CTP slightly. AMP was not hydrolysed. 3. These activities were inhibited by low concentration of ouabain. The concentration producing 50% inhibition was 0.1mum for ouabain-sensitive Mg(2+)-stimulated ATPase, 0.2mum for K(+)-stimulated ATPase, 0.1mum for (Na(+),K(+))-stimulated ATPase and 0.003mum for Na(+)-stimulated ATPase activity. 4. The ouabain-sensitive ATPase activities were inactivated by N-ethylmaleimide but the insensitive ATPase activity was not. 5. The three ouabain-sensitive ATPase activities were inhibited about 50% by 1mm-Ca(2+), whereas the ouabain-sensitive Mg(2+)-stimulated ATPase activity was activated by the same concentration of Ca(2+). The preparation was treated with ultrasonics at 20kcyc./sec. The 2min. ultrasonic treatment inactivated the ATPase activities by 50%. 7. The temperature coefficient Q(10) was 6.6 for K(+)-stimulated ATPase activity, 3.7 for (Na(+),K(+))-stimulated ATPase and 2.6 for Na(+)-stimulated ATPase. 8. Organic solvents inactivated the ATPase activities, to which treatment the K(+)-stimulated ATPase was the most resistant. 9. The phosphorylation of the enzyme preparation became less dependent on Na(+) with decreasing pH. This Na(+)-independent phosphorylation at low pH was sensitive to K(+) and hydroxylamine as well as the Na(+)-dependent phosphorylation at neutral pH.

Adenine Nucleotides↗
PubMed1980

Histo-chemical mapping of phosphomonoesterases in the gonads of Notopterus notopterus and Colisa fasciatus during different seasons. Part II. Adenosine triphosphatase and glucose-6-phosphatase.

Histochemical techniques described by McManus (1960) have been applied in the fishes, Notopterus notopterus and Colisa fasciatus, for the study of Glucose-60phosphatase and adenosine triphosphatase in the four stages of gonads in different seasons. It has been observed that the activity of adenosine triphosphatase is more intense in comparison to the activity of Glucose-6-phosphatase in all the stages i.e. I (immature), II (maturing), III (mature) and IV (spent) of the gonads in both the fishes. The general tendency of the adenosine triphosphatase and Glucose-6-phosphatase distribution in the gonads are much more remarkable in stage II in comparison to stage I, III and IV. The stage I seems to be the stage of synthesis of these enzymes. In stage III and IV, these enzymes show the tendency of declination with the time period. The possible role of these enzymes seems to be the transport of glucose across the cell membrane involving phosphorylation and dephosphorylation which depend on the different stages of gonad maturation.

Adenosine Triphosphatases↗
PubMed1977

Cytochemical localization of adenosine triphosphatase and thiamine pyrophosphatase in the synapases of rat's cerebral cortex.

Ultrastructural distribution of adenosine triphosphatase and thiamine pyrophosphatase in synapses of rat's cerebral cortex was studied. Adenosine triphosphatase activity in some synaptic vesicles and mitochondria, on pre- and postsynaptic membranes, as well as in the postsynaptic thickening was established. The reaction specificity was proved by means of some controls: various concentrations of ouabain, NaF, NiCl2, cysteine, substrate free medium and non-specific substrates - cocarboxylase and beta-glycerophosphate. At the thiamine pyrophatase reaction, the enzyme positive product was found on the membrane of some clear synaptic vesicles, on the singl sacs of smooth endoplasmic reticulum in the axon terminal, and bouton cell membrane. Substrate free medium, addition of cystein and substitution of orininal substrate with adenosine triphosphate and beta-glycerophosphate as controls were used. The fine structure localization of both enzymes in synaptic structures suggests their important role in the synaptic function.

Adenosine Triphosphatases↗
PubMed1975

[Activity and properties of adenosine triphosphatase in erythrocytes and various tissues (brain, liver, kidney, small intestine mucosa) of cattle].

In 15 samples of haemolysate of bovine erythrocytes, the splitting of phosphate from adenosine triphosphate average 158 +/- 63 X 10(-3) muMol/min/g haemolysate haemoglobin. Estimation of total adenosine triphosphatase in homogenates of various organs from cattle showed that spleen, liver, kidney and brain possessed high activity, while the activity was moderate in lung, myocardium and skeletal muscle, and low in endometrial mucosa and spinal cord. There was a relatively large proportion of Na-K-adenosine triphosphatase in brain and kidney. In various organs the activity of the enzyme was dependent upon the concentrations of Mg, Na, K and Ca. The inhibition of adenosine triphosphatase in various tissues by ouabain was studied. The optimum pH for the enzyme lay in the weakly alkaline region.

Adenosine Triphosphatases↗
PubMed2006

Determination of the big head carp myofibrillar (Aristichthys nobilis) adenosine triphosphatase activity by ion chromatography.

A method for the determination of adenosine triphosphatase (ATPase) activity of myofibrils of big head carp by using ion chromatography was introduced. Adenosine triphosphate (ATP), adenosine diphosphate (ADP) and orthophosphate (Pi) were separated completely. Recoveries for ATP, ADP and Pi were 98+/-5%, 97+/-4% and 98+/-5%, respectively. Pi liberated from ATP during reaction was monitored by ion chromatography using the suggested method. This method was applicable to the determination of myofibrils ATPase activity for quick quality evaluation of surimi.

Adenosine Triphosphatases↗
PubMed1979

Purification of the energy-transducing adenosine triphosphatase complex from Rhodospirillum rubrum.

The oligomycin- and N,N'-dicyclohexylcarbodiimide-sensitive adenosine triphosphatase complex extracted with Triton X-100 from the chromatophores of Rhodospirillum rubrum was extensively purified. The purification procedure included (diethylamino)ethylcellulose chromatography and glycerol gradient centrifugation. The specific activity of Mg2+-dependent ATP hydrolysis in the purified preparation increased about 11-fold, while that of Ca2+-dependent ATP hydrolysis increased 50-fold as compared with chromatophores. The purified adenosine triphosphatase complex dissociated into a maximum of eight different polypeptides upon electrophoresis in the presence of sodium dodecyl sulfate. The estimated subunit molecular weights were as follows: 56 000 (alpha), 50 000 (beta), 33 000 (gamma), and those ranging from 17 000 to 9400 for the remaining smaller subunits. The purified preparation was incorporated into phospholipid vesicles by using the freeze--thaw technique. The reconstituted vesicles catalyzed [32P]ATP exchange, which was almost completely inhibited by both oligomycin and N,N'-dicyclohexylcarbodiimide as well as by a protonophorous uncoupler, carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone.

Adenosine Triphosphatases↗
PubMed1971

Adenosine triphosphatase activity associated with mung bean mitochondria.

The properties of the adenosine triphosphatase activity associated with tightly coupled, time-stable mung bean (Phaseolus aureus Roxb.) mitochondria resemble those of intact animal mitochondria. Induction of adenosine triphosphatase activity by 2,4-dinitrophenol was inhibited by oligomycin, oxidizable substrates, and high concentrations of sucrose. Upon sonication, high rates of endogenous adenosine triphosphate hydrolysis resulted, an absolute requirement for Mg(2+) was manifested, stimulation by 2,4-dinitrophenol and inhibition by sucrose were eliminated, but sensitivity to oligomycin was retained.

Journal Article↗
PubMed1979

Histochemical localization of adenosine triphosphatase activity in bovine ruminal epithelium.

A fine-structural histochemical technique was used to localize magnesium-dependent adenosine triphosphatase (Mg-ATPase) activity in ruminal mucosa. Precipitate appeared on the cytoplasmic surface of the plasmalemma in cells of the upper stratum spinosum, the stratum granulosum, and the deepest layer of the stratum corneum. This ATPase activity was sensitive to glutaraldehyde fixation and possibly to ouabain, but was unaffected by sodium and potassium. The preponderance of Mg-ATPase activity in bovine ruminal epithelium may make it impossible to detect sodium-potassium-activated adenosine triphosphatase ((Na + K)-ATPase) activity histochemically. A Mg-ATPase activity also occurred in mitochondria of the stratum spinosum and stratum granulosum. None of the ruminal sections hydrolyzed adenosine diphosphate, inosine triphosphate, or beta-glycerophosphate when these compounds were used as substitute substrates for adenosine triphosphate. When adenosine-5'-monophosphate was the available substrate, a reaction product appeared in the same layers as Mg-ATPase activity, but the reaction product was confined to the intercellular space.

Adenosine Triphosphatases↗
PubMed1967

Sodium- and potassium-activated adenosine triphosphatase of gills: role in adaptation of teleosts to salt water.

The activity of adenosine triphosphatase activated by sodium and potassium ions is greatly increased in the gill and pseudobranch of the euryhaline killifish, Fundulus heteroclitus, after its adaptation to seawater. Adenosine triphosphatase activity in gills of fish in salt water is reduced by hypophysectomy. The data suggest that this enzyme is involved in the excretion of sodiumions by the gill and that the adaptive increase which occurs in seawater is influenced by the hypophysis.

Adaptation, Physiological↗
PubMed1975

Transient kinetic and isotopic tracer studies of the myosin adenosine triphosphatase reaction.

From transient kinetic studies of the Mg2+-dependent adenosine triphosphatase of myosin subfragment 1, prepared from rabbit skeletal muscle, a seven-step mechanism has been proposed. Features of this mechanism include two-step processes for ATP and ADP binding in which the binary complex isomerizes in addition to a rapid nucleotide association step. In the case of ATP a large negative standard free energy change is associated with the isomerization. An overall rate-limiting isomerization of the myosin-product complex prior to product release has been identified. Studies on the mechanism of cleavage of ATP bound to the active site indicate the process is readily reversible and can account for the observation that more than one oxygen of the product phosphate arises from water. This proposal has been substantiated by the finding that the oxygen atoms of the gamma-phosphoryl group of bound ATP also undergo extensive exchange with water.

Adenosine Diphosphate↗
PubMed1979

Requirement for negatively charged dispersions of phospholipids for interaction with lipid-depleted adenosine triphosphatase.

The basis of the requirement for a net negative charge on phospholipid dispersions able to re-activate lipid-depleted (Na++K+)-dependent adenosine triphosphatase was studied. The origin and density of the charge in phospholipid dispersions were varied before interaction with the adenosine triphosphatase protein, and the charge density on restored phospholipid-adenosine triphosphatase complexes was changed after interaction. The results indicated that: (a) re-activation requires a lamellar arrangement of the lipid molecules with sufficient density of negative charge, but not necessarily negatively charged phospholipid molecules; (b) the net charge appears to be necessary for the correct interaction between the enzyme protein and the phospholipids, although the amount of phospholipid that binds to the protein is also a function of the nature of the acyl chains; (c) it is not possible on the basis of these findings and those in the literature to decide unequivocally if the charge is also required for the enzyme reaction itself. The possible relevance of the findings to the situation in vivo is discussed in terms of the charge being concerned only with lipid-protein interaction.

Bile Acids and Salts↗
PubMed1975

Native (Na-+ + K-+)-dependent adenosine triphosphatase has two trypsin-sensitive sites.

Sodium and potassium adenosine triphosphatase ((Na + K)-ATPase) consists of two polypeptides, a large molecular weight polypeptide (MW 84,000 to 102,000) and a sialoglycoprotein (MW 35,000 to 57,000). Trypsin treatment of this complex selectively cleaves the large polypeptide into two fragments with molecular weights of 62,000 and 43,000. Simultaneously with the appearance of these fragments, (Na + K)-APTase activity is destroyed. Trypsin treatment of phosphorylated enzyme shows that he 43,000 molecular weight fragment is phosphorylated. If (Na + K)-ATPase is digested with trypsin in the presence of ATP, a 90,000 molecular weight fragment is produced. Disappearance of the large polypeptide, and loss of ATPase activity parallel the production of this fragment. Addition of strophanthidin to this mixture significantly lowers the amount of the 90,000 molecular weight fragment produced. Experiments on (Na + K)-ATPase of the red cell membrane suggest that trypsin is cleaving (Na + K)-ATPase at the interior surface of the plasma membrane.

Adenosine Triphosphatases↗
PubMed1988

Effect of high salt intake on sodium, potassium-dependent adenosine triphosphatase activity in the erythrocytes of normotensive men.

1. We measured ouabain-insensitive adenosine triphosphatase (ATPase), sodium, potassium-dependent adenosine triphosphatase (Na+,K+-ATPase) and intracellular Na+ and K+ in the erythrocytes of 19 healthy volunteers, before and after supplementation of their normal diet was 6.0-8.9 g of salt (102-137 mmol of NaCl) per day, for 5 days. 2. The subjects had a small but significant gain in weight. Mean plasma renin activity decreased from 1.57 to 0.73 pmol of angiotensin 1 h-1 ml-1 and plasma aldosterone from 0.46 to 0.24 nmol/l. 3. Total ATPase activity fell from 197.9 nmol of inorganic phosphate h-1 mg-1 during the control period to 173.5 during the high-salt period (P less than 0.0125). Na+, K+-ATPase activity fell from 162.2 to 141.4 nmol of inorganic phosphate h-1 mg-1 (P less than 0.05). Intracellular Na+ and intracellular K+ did not change. 4. These results are consistent with the hypothesis that salt-induced volume expansion causes the release of a factor inhibitory to the Na+ pump.

Adult↗
PubMed1976

Studies on calcium transport and calcium-dependent adenosine triphosphatase activity of erythrocyte membranes in hereditary spherocytosis.

Evidence has been recently presented of a relative deficiency of Ca2+ - dependent adenosine triphosphatase activity of erythrocyte membranes obtained from patients with hereditary spherocytosis. We have sought to confirm these findings by measuring calcium efflux from intact erythrocytes of patients with hereditary spherocytosis, as well as erythrocyte calcium concentrations, but find both these parameters to be normal. Ca2+-dependent adenosine triphosphatase activity, as well as Ca2+ -dependent membrane phosphorylation was also not found to be deficient in erythrocyte membranes from subjects with hereditary spherocytosis. These studies do not support the postulate that an accumulation of calcium affects the deformability of erythrocytes and their subsequent destruction in the spleen.

Adenosine Triphosphatases↗
PubMed1978

Cytochemical localization of acid phosphatase and adenosine triphosphatase in some avian mechanoreceptors.

Ultrastructural distribution of acid phosphatase and adenosine triphosphatase was studied in the receptor elements of HERBST and GRANDRY sensory corpuscles. Acid phosphatase activity was established in the elements of smooth and rough endoplasmic reticulum of perineural capsule cells, as well as in the secondary lysosomes of all cell types. Particular interest was paid on the activity of myelin-like dense bodies and some clear core vesicles belonging to the axoplasm of receptor nerve fibres. Adenosine triphosphatase activity was established on the membranes of receptor structures and pinocytotic vesicles. More deposits of electron dense material were localized on the axolemma of the non-myelinated portions of the receptor nerve fibres. The functional significance and importance of the both enzymes in the receptor structures was discussed.

Acid Phosphatase↗