Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Isocaloric replacement of either the fat or carbohydrate content of the diet by ethanol (36% of the total caloric intake) produced fatty infiltration of the liver in rats. The increase in hepatic triglyceride content was associated with a decrease in both ATP and glycogen contents. Increased activity of mitochondrial Mg(2+)-stimulated adenosine triphosphatase paralleled the increase in the free P(i) content of the liver homogenate. During the regression of the fatty liver, glycogen contents returned to normal within 24h of the removal of ethanol from the diet. Not until the third day after the withdrawal of ethanol had the Mg(2+)-stimulated adenosine triphosphatase activity and free P(i) content of the homogenate returned to normal. A slow regression of the triglyceride content from the liver occurred and by the fifth day both ATP and triglyceride concentrations had returned to the values observed in the rats given the liquid control diet.
Biochem J 1970 Sep
PMID:Biochemical aspects associated with an ethanol-induced fatty liver. 425 Aug 48

Trehalose-6,6'-dicorynomycolate (T66DCM), the cord factor of Corynebacterium diphtheriae, induced in vitro a swelling accompanied with a partially irreversible change of the mitochondrial membrane system in mouse liver. Preincubation of the mitochondrial suspension with T66DCM resulted in an inhibition of phosphorylation coupled to the oxidation of either succinate or a number of reduced nicotinamide adenine dinucleotide-linked substrates and a loss of respiratory control. T66DCM affected both electron transport and phosphorylation at coupling site II and uncoupled respiration and phosphorylation at coupling site III. T66DCM stimulated mitochondrial adenosine triphosphatase. The induction of adenosine triphosphatase by T66DCM and by 2,4-dinitrophenol was additive.
J Bacteriol 1971 Sep
PMID:Site of action of the cord factor of Corynebacterium diphtheriae in mitochondria. 425 39

The drinking of seawater and absorption of water along with sodium across the intestinal epithelium are well-known osmoregulatory events in marine teleosts. The insecticide DDT impairs fluid absorption in intestinal sacs from eels adapted to seawater. Furthermore, this functional impairment has an enzymatic basis; DDT also inhibits the (Na(+) and K(+)) activated, Mg(2+)-dependent adenosine triphosphatase in homogenates of the intestinal mucosa. Thus, the extreme sensitivity of teleosts to organochlorine pollutants may involve the disruption of osmoregulatory transport mechanisms.
Science 1971 Sep 17
PMID:DDT: disrupted osmoregulatory events in the intestine of the eel Anguilla rostrata adapted to seawater. 425 81

Phospholipids were found to be a constant component of rat glomerular basement-membrane preparations. The concentration fell during preparation of basement membrane by sonication of whole glomeruli, but then remained constant despite continued sonication. The proportions of the individual phospholipids were different from those of whole renal tissue or of isolated glomeruli. The basement-membrane preparations had no (Na(+)+K(+))-activated adenosine triphosphatase activity, an enzyme that is bound to plasma membranes. The concentration of lipid P was decreased on exposure in vivo or in vitro to antiserum against basement membrane; 7 days after injection of antiserum there was a change in the phospholipid composition, with a relative increase in phosphatidylcholine and a decrease in sphingomyelin content. The metabolic turnover rate of the lipid P remaining in the membrane was normal, as determined by (32)P incorporation. The loss of phospholipid was associated with decreases in the relative concentrations of hydroxyproline, hydroxylysine and glycine, and relative increases in proline, lysine, serine, threonine and valine. Administration of aminonucleoside and daunomycin produced proteinuria but did not cause a decrease in lipid P. Anticollagen and anti-lymphocyte sera that attached to the basement membrane but failed to produce proteinuria, also failed to affect the phospholipid content.
Biochem J 1972 Sep
PMID:Phospholipid of the rat glomerular basement membrane in experimental nephrosis. 426 92

The allosteric properties of the membrane-bound (Ca(2+))-adenosine triphosphatase of an unsaturated fatty acid auxotroph of Escherichia coli were studied in membranes with different fatty acid compositions. The Hill coefficient of the inhibition by Na(+) ranged from 1.4, in the case where the auxotroph was grown with cis-vaccenic acid as supplement, to 2.8 when grown on linolenic acid. The results indicate that no fatty acid is particularly involved in the allosteric phenomena. A correlation between the values of the Hill coefficient and the double bond index or the ratio of the double bond index saturated to the fatty acids of the membrane was found. These facts are interpreted as a modulation by the membrane fluidity of the allosteric behavior of the membrane-bound enzyme. The general biological character of this phenomenon is discussed in this paper.
J Bacteriol 1973 Sep
PMID:Regulation by membrane fluidity of the allosteric behavior of the (Ca2)-adenosine triphosphatase from Escherichia coli. 426 84

In the presence of ATP and of Mg(2+), human erythrocyte membranes show a phosphatase activity towards p-nitrophenyl phosphate which is activated by low concentrations of Ca(2+). The effect of Ca(2+) is strongly enhanced if either K(+) or Na(+) is also present. Activation of the p-nitrophenyl phosphate phosphatase by Ca(2+) reaches a half-maximum at about 8mum-Ca(2+) and is apparent only when the ion has access to the inner surface of the cell membrane. Ca(2+)-dependent phosphatase activity can only be observed if ATP is at the inner surface of the cell membrane, and the presence of ATP seems to be absolutely necessary, since either its removal or its replacement by other nucleoside triphosphates abolishes the activating effect of Ca(2+). The properties of the (ATP+Ca(2+))-dependent phosphatase are very similar to those of the Ca(2+)-dependent ATPase (adenosine triphosphatase), also present in erythrocyte membranes, which probably is involved in Ca(2+) transport in erythrocytes. The similarities suggest that both activities may be properties of the same molecular system. This view is further supported by the fact that p-nitrophenyl phosphate inhibits to a similar extent Ca(2+)-dependent ATPase activity and ATP-dependent Ca(2+) extrusion from erythrocytes.
Biochem J 1973 Sep
PMID:Calcium ion-dependent p-nitrophenyl phosphate phosphatase activity and calcium ion-dependent adenosine triphosphatase activity from human erythrocyte membranes. 427 34

Preincubating pig erythrocyte membranes with ATP enhances their ability to accumulate Ca(2+) against a concentration gradient. The extent of this increase is dependent on preincubation time over the period 0-60min. As the accessibility of outside membrane markers is decreased by preincubation and as accumulated Ca(2+) is not removed by EGTA [ethanedioxybis(ethylamine)tetra-acetate], it is suggested that ATP causes the formation of sealed inside-out vesicles which can transport Ca(2+) inward. The transport system requires ATP and Mg(2+) and exhibits an apparent dissociation constant for Ca(2+) of approx. 100mum. Since the dissociation constant for Ca(2+)-sensitive ATPase (adenosine triphosphatase) in these preparations is similar, it is concluded that this ATPase is responsible for Ca(2+) transport. Polyphosphoinositide concentrations are also increased during incubation with ATP; however, there is no change in their rate of synthesis or breakdown during Ca(2+) transport.
Biochem J 1974 Sep
PMID:Calcium ion transport by pig erythrocyte membrane vesicles. 428 3

Adenosine triphosphate and pyrophosphate prevent the loss of Ca(//)-activated adenosine triphosphatase activity caused by high concentrations of mercurial sulfhydryl reagent. They concomitantly prevent the transformation of myosin into faster-sedimenting products. This is adduced as support for the hypothesis that the strategic sulfhydryl group is not binding adenosine triphosphate at the active site, but is initiating a conformational change upon its reaction with the mercurial reagent.
Science 1965 Sep 17
PMID:Mercurial-induced transformation of myosin prevented by adenosine triphosphate and pyrophosphate. 428 26

1. The alanyl-s-RNA synthetase of tomato roots has been purified by ammonium sulphate precipitation, adsorption on calcium phosphate gel and DEAE-cellulose chromatography and its properties have been investigated. 2. Enzyme activity was measured by using the hydroxamate assay, the [(32)P]pyrophosphate-ATP-exchange assay and the [(14)C]alanyl-s-RNA assay. The purified enzyme was specific for l-alanine and was activated by Mg(2+) ions and to a smaller extent by Co(2+) and Mn(2+) ions. It was free from adenosine triphosphatase, pyrophosphatase and ribonuclease, and possessed a specific activity comparable with that of the most highly purified aminoacyl-s-RNA synthetases from animal and microbial systems. 3. The properties of the purified enzyme were similar in many respects to most other highly purified aminoacyl-s-RNA synthetases. It differed, however, in that the pH optimum of the hydroxamate assay was almost the same as that of the pyrophosphate-ATP-exchange assay and in requiring a high concentration of l-alanine for maximum activity (100mumoles/ml.). 4. The purified enzyme was not absolutely specific for tomato-root s-RNA; slight activity was also observed with yeast s-RNA. 5. The properties of this enzyme are fully consistent with the suggestion that the enzymic formation of alanyl-s-RNA proceeds via the intermediate formation of alanyl acyl-adenylate with the elimination of pyrophosphate from ATP. It remains to be shown the extent to which alanyl-s-RNA participates further in subsequent stages of protein synthesis in plants.
Biochem J 1965 Sep
PMID:The purification and properties of the alanyl-transfer ribonucleic acid synthetase of tomato roots. 428 91

1. The kinetics of inhibition of calf-intestinal alkaline phosphatase by inorganic phosphate, fluorophosphate, inorganic pyrophosphate, beta-glycerophosphate and adenosine 5'-triphosphate in the range pH8-10 were investigated. The reference substrate was 4-methylumbelliferyl phosphate. 2. The inhibitions were ;mixed' in that both K(m) and V were affected, but the competitive element was by far the stronger. 3. In each case the pH profile for the competitive K(i) was similar to the pH profile for K(m). Since the K(m) and K(i) values both change 100-fold over the pH range 8-10, it is concluded that the inhibitors compete with the substrate for the same active site. 4. It was also found that the enzyme preparation hydrolysed fluorophosphate, pyrophosphate and adenosine 5'-triphosphate as readily as it hydrolysed 4-methylumbelliferyl phosphate and beta-glycerophosphate. Each pH-activity curve, however, had a different shape, but with the exception of pyrophosphate the activity approached the same maximum value at high pH. 5. Attempts to separate the phosphomonoesterase and pyrophosphatase activities by column chromatography were not successful, and the results of other experiments listed suggest that the two activities are a property of the same enzyme. 6. The effect of Mg(2+) ions is briefly mentioned: the phosphomonoesterase activity is enhanced whereas the pyrophosphatase and adenosine triphosphatase activities are strongly inhibited in the presence of excess of Mg(2+) ions.
Biochem J 1967 Sep
PMID:Studies on alkaline phosphatase. Inhibition by phosphate derivatives and the substrate specificity. 429 74


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