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)

Palmitoyl CoA inhibited EDTA-ATPase of heavy meromyosin (HMM) prepared from rabbit skeletal muscle. The concentration for half maximum inhibition of EDTA-ATPase was about 18 microM. Myristoyl CoA, the other long chain fatty acyl CoA, also inhibited EDTA-HMM ATPase, but CoA and short chain CoA thioesters, such as butyryl CoA, acetoacetyl CoA and acetyl CoA, at 40 microM hardly inhibited EDTA-ATPase. Less than 20% inhibition of EDTA-HMM ATPase was obtained with Na-palmitate and Na-myristate at 40 microM, whereas about 90% inhibition of the enzyme occurred in the presence of 40 microM palmitoyl CoA and myristoyl CoA. Palmitoyl carnitine, as well as carnitine, failed to inhibit EDTA-HMM-ATPase. The inhibition of palmitoyl CoA of EDTA-ATPase was reversed by bovine serum albumin and spermine. Mg2+-HMM ATPase activity was enhanced by palmitoyl CoA at 2, 5, and 10 microM. About a 25% increase in Mg2+-HMM ATPase activity was obtained at 5 and 10 microM. At higher concentrations than 20 microM, the enzyme was inhibited by palmitoyl CoA and the degree of inhibition was related to the concentration of the CoA thioester. At 80 microM, the activity was about 15% of the maximum value. The efficacy of myristoyl CoA on Mg2+-ATPase was almost the same as that of palmitoyl CoA. Mg2+-ATPase activity was not enhanced by CoA, butyryl CoA, acetoacetyl CoA, Na-myristate, Na-palmitate, palmitoyl carnitine, or carnitine at 10 microM, and was hardly reduced by these substances at 40 microM. Serum albumin and spermine also canceled, to some extent, these effects of palmitoyl CoA on Mg2+-ATPase.
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PMID:Inhibition of palmitoyl CoA of EDTA- and Mg2+-ATPase of heavy meromyosin from rabbit skeletal muscle. 611 60

Acetyl CoA carboxylase was purified from liver of fasted-refed rats to near homogeneity, based on electrophoretic analysis and biotin content. These preparations contained an endogenous protein kinase that catalyzed the transfer of radioactive phosphate from [gamma-32P]ATP to acetyl CoA carboxylase, accompanied by a decrease in acetyl CoA carboxylase activity. Phosphate incorporated into acetyl CoA carboxylase was removed when the preparation was incubated with partially purified phosphorylase phosphatase catalytic subunit with regain of enzymatic activity. This endogenous protein kinase was shown not to be affected by either cyclic-AMP-dependent protein kinase inhibitor, EGTA, or trifluoperazine. The addition of either cyclic-AMP or purified cyclic-AMP-dependent protein kinase catalytic subunit to the purified acetyl CoA carboxylase preparation increased protein phosphorylation but had no further effect on acetyl CoA carboxylase activity. Purified acetyl CoA carboxylase was shown to act as an ATPase during the phosphorylation reaction.
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PMID:Regulation of purified rat liver acetyl CoA carboxylase by phosphorylation. 613 2

Activation of lymphocytes by antigens and mitogens can effectively be prevented by ouabain, a known inhibitor of (Na+ + K+)-ATPase. Recently it was shown that lowering of intracellular levels of monovalent cations is not involved in the inhibitory effect of ouabain. (Na+ + K+)-ATPase was found to be closely associated with acyl-CoA : lysophosphatidylcholine acyltransferase in the plasma membrane of lymphocytes. Both enzymes are activated as an immediate consequence of mitogen binding. Human peripheral lymphocytes were stimulated with concanavalin A. Ouabain suppressed the induction of RNA and DNA synthesis in a concentration-dependent way. Increase of RNA synthesis was suppressed only if the glycoside were added within the first hours of activation. If ouabain was added later, incorporation of uridine remained at the rate that was reached at the time of glycoside administration, pointing to an early event where ouabain may be operative. Ouabain, in a dose-dependent manner similar to that affecting RNA and DNA synthesis, inhibited the increase in the incorporation of oleate into phospholipids in stimulated lymphocytes, whereas the turnover of phospholipid fatty acids in resting lymphocytes was unaffected. Increasing extracellular K+ concentrations reversed the binding of ouabain to lymphocytes. Simultaneously, the inhibition of stimulated RNA synthesis was decreased and the inhibition of oleate incorporation was reversed. These results suggest that the suppression of lymphocyte activation by ouabain is due to the inhibition of membrane phospholipid metabolism mediated by (Na+ + K+)-ATPase.
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PMID:Inhibition of lymphocyte activation by ouabain. Interference with the early activation of membrane phospholipid metabolism. 617 Mar 33

ATPase of 14S dynein, extracted from spermatozoa of the sea urchin, Hemicentrotus pulcherrimus, and partially purified by sucrose density gradient centrifugation, was inhibited non-competitively by palmitoyl CoA at concentrations higher than 20 microns, and was stimulated at concentrations between 2 microns and 10 microns. The effects of palmitoyl CoA on dynein ATPase were reversed by bovine serum albumin (1 mg/ml) and spermine (0.1 and 1 mM). Myristoyl CoA exerted effects similar to those of palmitoyl CoA. Short chain fatty acyl CoAs, such as butyryl CoA, propionyl CoA and acetyl CoA, CoA, Na-palmitate, Na-myristate, and palmitoyl carnitine had hardly any effect on dynein ATPase. Palmitoyl CoA failed to inhibit purified CF1 ATPase from chloroplasts of spinach, ATPase of rat liver mitochondria and alkaline phosphatase from calf intestine.
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PMID:Inhibition by palmitoyl CoA of dynein ATPase from sea urchin spermatozoa. 621

Plasma membrane phospholipids were modified by incubation in the presence of linoleyl-CoA with or without added lysolecithin (LPC) for various length of time. In the absence of LPC, a maximum of 10 nmoles linoleyl-phosphatidylcholine (PC) were synthesized and the ATPase specific activities were not affected whereas in the presence of LPC, when linoleyl-PC synthesis rose from 10 to 80 nmoles, the ATPase activities were decreased. The decrease was similar in the Na,K- or in the Mg-dependent-ATPase and reached maximally 30-40%. LPC by itself did not modify the ATPases. A concomitant decrease in DPH polarization was observed when linoleate was incorporated into phospholipids. We concluded that the decreased ATPase specific activities may be due to an increased fluidity of membranes produced by linoleyl- PC synthesis. We compare this modulation of ATPases by the membrane fluidity with the specific effect of linoleyl- PC species on adenylate cyclase.
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PMID:Linoleate incorporation into rat liver membranes phospholipids: effect on plasma membrane ATPase activities and physical properties. 623 79

The effect of amphiphilic lipid intermediates on the Na+-stimulatable activity of the Na+-K+-ATPase of sarcolemma from adult canine cardiac myocytes was studied. Sarcolemma (mean Na+-stimulatable ATPase activity of 73 mumol.mg sarcolemmal protein-1.h-1) was preincubated (37 degrees C for 10 min at pH 7.2) or rapidly mixed at 0 degrees C with amphiphilic lipid intermediates prior to dilution and assay of enzyme activity. Their effects were dependent on temperature, initial concentration, and the ratio of bound amphiphile to sarcolemmal protein. In particular, pretreatment of freshly prepared sarcolemma at 0 degrees C with arachidonyl CoA (up to 0.25 mM) caused 110% stimulation above control activity; palmitoyl CoA or palmitoyl carnitine under the same conditions caused no significant effect. Despite strong binding to the sarcolemmal vesicles, palmitoyl carnitine (up to 0.4 mM or 5 mumol/mg protein) and palmitoyl CoA (0.1 mM or 1.0 mumol of membrane-bound palmitoyl CoA/mg protein) were ineffective even with preincubation. Palmitoyl CoA was inhibitory above this level. Preincubation (22 degrees C for 10 min) with lysophosphatidylcholine only produced inhibition (40% at 0.75 mM). Thus fatty acyl thioesters of CoA and lysophosphatidyl choline but not palmitoyl carnitine perturb sarcolemmal Na+-K+-ATPase activity.
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PMID:Effects of fatty acid intermediates on Na+-K+-ATPase activity of cardiac sarcolemma. 627 56

In this report the disturbances in biochemistry of the heart muscle exposed to alcohol are delineated. All elements of cellular substructures are affected. In plasma membranes, (Na+ + K+)-activated ATPase (EC 3.6.1.3) is inhibited. Mitochondrial damage consists in diminished respiratory function and calcium uptake and binding. High-energy phosphates remain intact. Alcohol also affects the malate-aspartate shuttle. Acetaldehyde, a metabolite of ethanol, has a direct effect on myocardial protein synthesis through microsomal inhibition; however, the development of cardiac hypertrophy is not affected. Malfunction of sarcoplasmic reticulum is evidenced by disturbances in calcium binding and uptake. Effects of ethanol on the contractile machinery are deficiencies in the turnover rate of chemical into mechanical energy (diminished Vmax), and in the number of cross-bridges formed (P0). It increases stiffness of series elastic elements. There is diminished fatty acid oxidation with increased esterification. The involvement of CoA synthetase (EC 6.2.1.1), palmityl-carnitine transferase (EC 2.3.1.7), and pyruvate dehydrogenase complex in disturbed fatty acid oxidation is not certain. The role of catalase in myocardial ethanol oxidation was examined. Ethanol activates myocardial catalase-H2O2 complex (EC 1.11.1.6). The biochemical basis of fetal alcohol syndrome is low hepatic alcohol dehydrogenase (EC 1.1.1.1) activity during fetal life.
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PMID:Effect of alcohol on the heart and cardiac metabolism. 628 54

Adenine nucleotide translocase (EC 3.6.1.3.), pyruvate dehydrogenase (active and total forms, EC 1.2.4.1) and the long chain acyl CoA content were measured in liver and kidney from normal and alloxan-diabetic rats. The long chain acyl CoA content was significantly increased in liver, but not in kidney, in the diabetic group. Adenine nucleotide translocase activity was decreased in liver and raised in the kidney of alloxan-diabetic rats relative to the control group. Pyruvate dehydrogenase (active) was inhibited to a similar degree in both tissues in diabetes. The results are discussed in the light of the possible regulatory role of long chain acyl CoA and the diverse metabolic demands of the two tissues in diabetes.
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PMID:Differential response of liver and kidney adenine nucleotide translocase and pyruvate dehydrogenase activity to alloxan diabetes. The possible regulatory role of long chain acyl CoA. 630 7

Sarcolemma from adult canine cardiac myocytes (Na+-K+-ATPase activity 71.8 +/- 3.4 mumol . mg protein-1 . h-1) was preincubated (10 min at 37 degrees C, pH 7.2) with 1) 5-250 microM arachidonyl CoA, 2) 2.5 nM- 2.5 mM propranolol, 3) 5-250 microM arachidonyl CoA plus 2.5 mM propranolol or 4) 2.5 nM-2.5 mM propranolol plus 50 microM arachidonyl CoA; after preincubation the Na+-stimulatable activity was assayed. Arachidonyl CoA alone (50 microM, expt 1) elicited maximum stimulation (89% above control), whereas concentrations greater than 125 microM were inhibitory. Preincubation with propranolol alone (expt 2) had no significant effect on activity. However, when membranes were pretreated with both arachidonyl CoA and 2.5 mM propranolol (expt 3) activity was significantly inhibited. Preincubation with concentrations of propranolol greater than 25 microM were required to reverse the stimulatory effect of 50 microM arachidonyl CoA (expt 4). Propranolol and arachidonyl CoA do not have to be present simultaneously to produce an inhibitory effect. Activity was greatly inhibited (87%) when membranes were preincubated with 100 microM arachidonyl CoA followed by addition of 2.5 mM propranolol; no inhibition was observed if preincubation conditions were reversed. These data suggest that propranolol-induced inhibition of the Na+-K+-ATPase is reversible but becomes irreversible when sarcolemma is pretreated with the fatty acyl CoA, either prior to or during propranolol preincubation.
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PMID:Cardiac sarcolemmal Na+-K+-ATPase: combined effects of propranolol and arachidonyl CoA. 630 34

Male rats developed fatty liver after being fed on an ethanol-containing diet for 31 days. Liver mitochondria from these animals catalysed ATP synthesis at a slower rate when compared with mitochondria from pair-fed control rats (control mitochondria), and demonstrated lowered respiratory control with succinate as substrate, owing to a decrease in the State-3 respiratory rate. Respiration in the presence of uncoupler was comparable in mitochondria from both groups of rats. Translocation of both ATP and ADP was decreased in mitochondria from ethanol-fed rats, with ADP uptake being lowered more dramatically by ethanol feeding. Parameters influencing adenine nucleotide translocation were investigated in mitochondria from ethanol-fed rats. Experiments performed suggested that lowered adenine nucleotide translocation in these mitochondria is not the result of inhibition of the translocase by either long-chain acyl-CoA derivatives or unesterified fatty acids. Analysis of endogenous adenine nucleotides in these mitochondria revealed lowered ATP concentrations, but no decrease in total adenine nucleotides. In experiments where the endogenous ATP in these mitochondria was shifted to higher concentrations by incubation with oxidizable substrates or defatted bovine serum albumin, the rate of ADP translocation was increased, with a linear correlation being observed between endogenous ATP concentrations and the rate of ADP translocation. The depressed ATP concentration in mitochondria from ethanol-fed rats suggests that the ATP synthetase complex is replenishing endogenous ATP at a slower rate. The lowered ATPase activity of the ATP synthetase observed in submitochondrial particles from ethanol-fed animals suggests a decrease in the function of the synthetase complex. A decrease in the rate of ATP synthesis in mitochondria from ethanol-fed rats is sufficient to explain the decreased ADP translocation and State-3 respiration.
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PMID:Control of adenine nucleotide metabolism in hepatic mitochondria from rats with ethanol-induced fatty liver. 709 25


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