Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nitrofurantoin resistance brought about decreased level of membrane bound ATPase activity in Vibrio el tor as compared to the normal strain while phospholipid as well as total lipid levels in the membrane fraction was increased. Mg++ was found to be the mose effective co-factor for ATPase. At higher concentrations of sodium and potassium ions, ATPase of normal and nitrofurantoin resistant Vibrio el tor responded quite differently. A soluble ATPase extract having low phospholipid content was found to be activated by the phospholipid extracts of Vibrio el tor, phosphatidyl ethanolamine, and also by phosphatidyl choline which is not a constituent of the membrane preparation of Vibrio el tor strains.
Acta Microbiol Pol 1981
PMID:Studies on membrane ATPase activity and lipid level in vibrio el tor under normal and nitrofurantoin resistant conditions. 617 24

Intestinal absorption of sodium, potassium, calcium and magnesium was studied in rats by the method of intestinal perfusion using ouabain as an inhibitor of sodium-potassium dependent ATPase. At the same time the activity of ATPase and phosphatase were determined in homogenates of intestinal mucosa. A significant effect on the concentration of the determined ions was demonstrated in the transport of these ions, and also an unquestionable participation of intestinal ATPase in the direction and intensity of this transport. It was found that the multidirectional effect of ouabain on the transport of cations depended on their concentration. In the case of concentrations of cations similar to those in the mean food rations it has been demonstrated that ouabain increased the absorption of sodium, potassium and calcium and inhibited the absorption of magnesium. With a threefold higher ions concentration the absorption of potassium and magnesium was inhibited, without changing the transport of sodium and calcium. The possible explanation of the mechanism of these effects is discussed.
Acta Physiol Pol
PMID:Certain aspects of the mechanism of intestinal transport of sodium, potassium, calcium and magnesium in rats. 625 46

The concentration of di-2-ethylhexylphthalate (DEHP) was determined in whole blood, packed red cells and plasma of the blood collected into blood plastic bags manufactured by McGaw, Biotest or Polfa, in samples withdrawn immediately after collection and 1, 2 and 3 weeks later. ATPase activity and electrolyte (K+, Na+, Mg++) composition of erythrocytes were tested and possible morphological changes were inspected in phase-contrast microscope. Platelet aggregation induced by ADP, collagen and adrenaline was also investigated. Blood stored in glass bottles served as a standard. The DEPH concentrations were similar in samples contained in various bags. Maximum DEPH concentration in the whole blood, after 3 weeks of storage, attained 52 microgram/cm3. ATP-ase activity was more rapidly depressed in the blood kept in bags instead of glass bottles. Erythrocyte morphology and results of platelet function tests remained unaffected.
Pol J Pharmacol Pharm
PMID:The effect of plasticizers of plastic material bags on biochemical and morphological changes of morphotic blood elements. 745 4

Diminished activities of Na/K/ATPase and Na/K/2Cl-cotransport in arterial smooth muscles lead to vasoconstriction. We found it interesting to check if a decrease in activities of those ion transports are present in other diseases with smooth muscles hyperreactivity; bronchial asthma and COPD. The study was performed on lymphocytes collected from 57 patients with atopic asthma, nonatopic asthma and COPD; the groups consisted of 18, 28 and 11 patients respectively. Control group was composed of 15 healthy subjects. There were no significant differences in Na/K/-ATPase and Na/K/2Cl-cotransport activities either in the exacerbation compared to the remission in the examined group, or in patients versus controls. Na/K-ATPase activity was strongly dependent on pO2.
Pneumonol Alergol Pol 1994
PMID:[Activity of sodium-potassium adenosinetriphosphatase and cotransport of sodium, potassium and chloride ions in patients with bronchial asthma and chronic obstructive pulmonary diseases]. 795 Oct 87

The effects of Mg2+ and bicarbonate on the kinetics of ITP hydrolysis by soluble ATPase (F1) from human placental mitochondria were studied. Increasing amounts of Mg2+ at fixed ITP concentration, caused a marked activation of F1 followed by inhibition at higher Mg2+ concentration. The appropriate substrate for the mitochondrial F1 seems to be the MgITP complex as almost no ITP was hydrolysed in the absence of magnesium. Mg2+ behaved as a competitive inhibitor towards the MgITP complex. In this respect the human placental enzyme differ from that from other sources such as yeast, beef liver or rat liver. The linearity of the plot presenting competitive inhibition by free Mg2+ of MgITP hydrolysis (in the presence of activating bicarbonate anion) suggests that both Mg2+ and MgITP bind to the same catalytic site (Km(MgITP) = 0.46 mM, Ki(Mg) = 4 mM). When bicarbonate was absent in the ITPase assay, placental F1 exhibited apparent negative cooperativity in the presence of 5 mM Mg2+, just as it did with MgATP as a substrate under similar conditions. Bicarbonate ions eliminated the negative cooperativity with respect to ITP (as the Hill coefficient of 0.46 was brought to approx. 1), and thus limited inhibition by free Mg2+. The results presented suggest that the concentration of free magnesium ions may be an important regulatory factor of the human placental F1 activity.
Acta Biochim Pol 1994
PMID:Mitochondrial adenosine triphosphatase from human placenta--inhibition by free magnesium ions of ITP hydrolysis. 803 Mar 73

In Saccharomyces cerevisiae, the pma1 mutations controlling the vanadate resistance of the H(+)-ATPase activity from the plasma membrane, map on chromosome VII in the vicinity of pdr1 mutations controlling multiple drug resistance. However, the pma1-1 mutants exhibit a genotype and a multidrug resistant phenotype quite different from those obtained for pdr1 mutants. Quantitative modifications of cycloheximide and N,N'-(p-xylylidene)-bis-aminoguanidine-2HCl resistance are observed in diploids containing the pma1 and pdr1 genes in trans configuration. Each of the pdr1 mutations interacts with pma1 as shown by a decrease in the ATPase activity in pdr1/pma1 diploids. The in vitro resistance of ATPase activity to vanadate is totally or partially suppressed in pdr1 mutants in haploid double mutants. These results suggest that the expression of PMA1 might be controlled by the PDR1 gene product.
Acta Biochim Pol 1993
PMID:Interactions between the gene products of pma1 encoding plasma membrane H(+)-ATPase, and pdr1 controlling multiple drug resistance in Saccharomyces cerevisiae. 814 Aug 23

The activity of Na+,K(+)-ATPase in the microsomal fraction of rabbit kidney cortex was strongly decreased by ischemia and increased slightly, but not significantly, after reperfusion. These changes were correlated with a dramatic increase in lipid peroxidation in microsomes isolated from both ischemic and reperfused kidneys. This correlation may point to irreversible impairment of the enzymatic function under the influence of either oxygen free radicals or lipid peroxidation.
Acta Biochim Pol 1993
PMID:Na+,K(+)-ATPase activity of rabbit kidney cortex membranes in ischemia and reperfusion. 814 Aug 29

The effect of long-term treatment with propafenone, metoprolol and amiodarone was studied on the activity of Na,K-adenosine triphosphatase in lymphocytes and the plasma level of cAMP in patients with ventricular arrhythmias. The investigations were carried out in 86 patients with cardiac dysrhythmias caused by coronary artery disease, hypertension, post-inflammatory and alcohol cardiomyopathy and preexcitation syndrome. Propafenone was used in treatment in 31 patients, metoprolol in 30, amiodarone in 25. The activity of of Na,K-adenosine triphosphatase in lymphocytes was estimated by the method of Heagerty et al. The plasma level of cAMP was measured radioimmunologically. Disappearance of ventricular arrhythmias after treatment was accompanied by increase in activity of of Na,K-adenosine triphosphatase and decrease in plasma level of cAMP regardless of which drug was used. Ineffective treatment did not affect both parameters.
Pol Arch Med Wewn 1995 Jul
PMID:[The effect of treatment with propafenone, metoprolol and amiodarone on lymphocyte sodium efflux and level of cAMP in serum]. 852 94

The need for new mechanistic classes of broad spectrum antifungal agents has prompted development of the membrane sector and ectodomain of the plasma membrane proton pumping ATPase as an antifungal target. The fungal proton pump is a highly abundant, essential enzyme in Saccharomyces cerevisiae. It belongs to the family of P-type ATPases, a class of enzymes that includes the Na+,K(+)-ATPase and the gastric H+,K(+)-ATPase. These enzymes are cell surface therapeutic targets for the cardiac glycosides and several anti-ulcer drugs, respectively. The effects of acid-activated omeprazole show that extensive inhibition of the S. cerevisiae ATPase is fungicidal. Fungal proton pumps possess elements within their transmembrane loops that distinguish them from other P-type ATPases. These loops, such as the conformationally sensitive transmembrane loop 1+2, can attenuate the activity of the enzyme. Expression in S. cerevisiae of fully functional chimeric ATPases that contain a foreign target comprising transmembrane loops 1+2 and/or 3+4 from the fungal pathogen Candida albicans suggests that these loops operate as a domain. The chimera containing C. albicans transmembrane loops 1+2 and 3+4 provides a prototype for mutational analysis of the target region and the screening of inhibitors directed against opportunistic fungal pathogens. Panels of mutants with modified ATPase regulation or with altered cell surface cysteine residues are also described. Information about the ATPase membrane sector and ectodomain has been integrated into a model of this region.
Acta Biochim Pol 1995
PMID:Targeting the fungal plasma membrane proton pump. 885 38

Inhibition of respiration by glucose, known as the Crabtree effect, has been observed in several tumours and some other highly glycolytic cells and tissues. Among mechanisms proposed to explain this effect were: competition between glycolysis and respiration for ADP or for inorganic phosphate, change of intracellular pH, change in the permeability of mitochondrial membranes, specific regulatory behavior of glycolytic enzymes, and specific enzyme topography within the cell. None of these proposals alone seems satisfactory. The present article describes the research carried out in the author's laboratory, pointing to the role of Ca2+ in the mechanism of the Crabtree effect. This supposition is based on the following observations: (1) in Ehrlich ascites tumour cells glucose elicits a steady increase of the cytoplasmic concentration of free Ca2+; (2) isolated Ehrlich ascites mitochondria and mitochondria within digitonin-permeabilised cells, preloaded with Ca2+, exhibit a depression of State 3 respiration and lowering of the rate of ATP synthesis; (3) ATPase activity of toluene-permeabilised Ehrlich ascites mitochondria becomes substantially inhibited at micromolar concentrations of Ca2+; (4) Ca2+ potentiates the effect of the inhibitory subunit of F1F0-ATPase. These results allow to hypothesize on the following sequence of events: (1) glucose elevates the cytoplasmic concentration of Ca2+; (2) this elicits an increased accumulation of Ca2+ in mitochondria; (3) loading of mitochondria with Ca2+ leads to an increased association of the inhibitory subunit with F1F0 which results in (4) the inhibition of coupled respiration. The importance of these mechanisms for glycolytic and rapidly proliferating cells is discussed.
Acta Biochim Pol 1996
PMID:The Crabtree effect: a new look at the old problem. 886 81


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