Na+/K+-ATPase Activity of Erythrocyte Membranes

1973 ◽  
Vol 27 (6) ◽  
pp. 399-400 ◽  
Author(s):  
GianCarlo Secchi ◽  
Lorenzo Alessio ◽  
Giovanni Cambiaghi
Keyword(s):  
Atpase Activity ◽  
Erythrocyte Membranes

scholarly journals Calcium-ATPase Activity in Cystic Fibrosis Erythrocyte Membranes: Decreased Activity in Patients with Pancreatic Insufficiency

1984 ◽  
Vol 18 (9) ◽  
pp. 890-895 ◽  
Author(s):  
Dorr G Dearborn ◽  
Robert J Wityk ◽  
Lynelle R Johnson ◽  
Louis Poncz ◽  
Robert C Stern
Keyword(s):  
Cystic Fibrosis ◽  
Atpase Activity ◽  
Pancreatic Insufficiency ◽  
Calcium Atpase ◽  
Erythrocyte Membranes

Changes in Erythrocyte Membrane Ouabain-Sensitive Adenosine Triphosphatase after Renal Transplantation

1975 ◽  
Vol 48 (3) ◽  
pp. 239-242 ◽  
Author(s):  
C. H. Cole ◽  
R. Maletz
Keyword(s):  
Renal Transplantation ◽  
Atpase Activity ◽  
Erythrocyte Membrane ◽  
Adenosine Triphosphatase ◽  
Inorganic Phosphorus ◽  
Erythrocyte Membranes ◽  
Healthy Controls ◽  
Intracellular Electrolytes ◽  
Transplant Patients ◽  
The Mean

1. Intracellular electrolytes, and erythrocyte membrane adenosine triphosphatase (ATPase) activity, was studied in twenty patients after renal transplantation. 2. The mean ouabain-sensitive ATPase activity in the erythrocyte membranes of the transplant patients was 122 nmol of inorganic phosphorus (Pi) h−1 mg of tissue−1 (sem 14), compared with 62 nmol of Pi h−1 mg of tissue−1 (sem 8) in a group of paired, healthy controls. 3. The increase in ouabain-sensitive ATPase was most marked in the 4 months after transplantation. However, a significant increase in ouabain-sensitive ATPase persisted for more than 8 months after transplantation. 4. This increase in ouabain-sensitive ATPase was associated with a decrease in intracellular sodium in the erythrocytes of the transplant patients.

Effect of a Hyperlipidic Diet on Lipid Composition, Fluidity, and (Na+-K+)ATPase Activity of Rat Erythrocyte Membranes

1989 ◽  
Vol 8 (1) ◽  
pp. 11-18 ◽  
Author(s):  
A. Bordoni ◽  
P. L. Biagi ◽  
G. Parenti Castelli ◽  
S. Hrelia ◽  
C. A. Rossi ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Lipid Composition ◽  
Erythrocyte Membranes ◽  
Hyperlipidic Diet

Combined effects of lead and edta on Na+,K+‐ATPase activity of erythrocyte membranes

1983 ◽  
Vol 12 (4-6) ◽  
pp. 721-730 ◽  
Author(s):  
Ichiro Karai ◽  
Su Ill Lee ◽  
Shun'ichi Horiguchi ◽  
Koichi Fukumoto ◽  
Shinya Matsumura ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Erythrocyte Membranes ◽  
Combined Effects

scholarly journals A protein activator of Mg2+-dependent, Ca2+-stimulated ATPase in human erythrocyte membranes distinct from calmodulin

1980 ◽  
Vol 187 (2) ◽  
pp. 507-513 ◽  
Author(s):  
Douglas Mauldin ◽  
Basil D. Roufogalis
Keyword(s):  
Atpase Activity ◽  
Sucrose Gradient ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Erythrocyte Membranes ◽  
Dependent Manner ◽  
Calmodulin Binding ◽  
Heat Stable ◽  
Protein Activator ◽  
Human Erythrocyte Membranes

Treatment of extensively washed erythrocyte membranes with 0.1mm-EDTA decreased their Mg2+-dependent, Ca2+-stimulated ATPase [(Mg2++Ca2+)-ATPase] activity. An activator released by this treatment restored the (Mg2++Ca2+)-ATPase to its original value in a Ca2+-dependent manner. This activator was different from calmodulin, as determined by a number of criteria. It was retained on an Amicon XM-100 ultrafiltration membrane (molecular-weight cut-off 100000); it appeared in the void volume of Sephadex G-100 and G-75 columns; it was not retained on a DEAE-cellulose ion-exchange column at ionic strengths similar to those used to retain calmodulin; and it maximally activated (Mg2++Ca2+)-ATPase activity less than calmodulin and at a higher Ca2+ concentration. Like calmodulin, the activator is heat-stable. The activator fraction isolated on a 2.5–15% sucrose gradient in 0.16m-KCl showed a single band of mol.wt. 63000 and no calmodulin on 10%-polyacrylamide/sodium dodecyl sulphate gels. A trace amount of calmodulin was detected in the activator fraction by radioimmunoassay (approx. 10pg/ml of ‘ghosts’), but this amount was insufficient to account for the (Mg2++Ca2+)-ATPase activation. Furthermore, calmodulin-binding protein failed to inhibit (Mg2++Ca2+)-ATPase activity by more than 10–20% in the membrane preparations from which the activator was extracted. It was concluded that erythrocyte membranes contain a (Mg2++Ca2+)-ATPase activator that may attenuate the activation of the Ca2+-transport ATPase by calmodulin.

scholarly journals Structure-activity relationships of retinoids as inhibitors of calmodulin-dependent human erythrocyte Ca2+-ATPase activity and calmodulin binding to membranes

1991 ◽  
Vol 277 (3) ◽  
pp. 603-606 ◽  
Author(s):  
F B Davis ◽  
T J Smith ◽  
P J Davis ◽  
S D Blas
Keyword(s):  
Enzyme Activity ◽  
Retinoic Acid ◽  
Atpase Activity ◽  
Human Erythrocyte ◽  
Enzyme Inhibitors ◽  
Ring Structure ◽  
Erythrocyte Membranes ◽  
Calmodulin Binding ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid

All-trans retinoic acid displaces the binding of radiolabelled calmodulin to human erythrocyte membranes, and inhibits the activity of plasma membrane Ca(2+)-stimulated, Mg(2+)-dependent ATPase (Ca(2+)-ATPase; EC 3.6.1.3). This enzyme is dependent upon the action of calmodulin. In this study we explored the structural attributes of the retinoids which confer this ability to inhibit enzyme activity and calmodulin binding. With respect to the fatty acid side-chain, a clear requirement for inhibition is a trans-configuration of the polar end-group. The importance of the ring structure is indicated by the ineffectiveness of polyprenoic acid and a benzene ring retinoid analogue as inhibitors of enzyme activity and calmodulin binding. There was good correlation between the relative potencies of the analogues as enzyme inhibitors and as inhibitors of calmodulin binding. The ability of selected retinoid analogues, at physiological concentrations with respect to all-trans retinoic acid, to inhibit erythrocyte Ca(2+)-ATPase activity and membrane binding of calmodulin underscores the structurally specific effects of these compounds on the interaction of calmodulin with the membrane-bound enzyme.

scholarly journals The effect of calmodulin on the phosphoprotein intermediate of Mg2+-dependent Ca2+-stimulated adenosine triphosphatase in human erythrocyte membranes

1981 ◽  
Vol 194 (2) ◽  
pp. 481-486 ◽  
Author(s):  
D A Jeffery ◽  
B D Roufogalis ◽  
S Katz
Keyword(s):  
Steady State ◽  
Atpase Activity ◽  
Turnover Rate ◽  
Erythrocyte Membranes ◽  
Steady State Concentration ◽  
Transport Atpase ◽  
Dependent Atpase ◽  
Mgcl2 Concentration ◽  
Human Erythrocyte Membranes ◽  
State Concentration

The effect of calmodulin on the formation and decomposition of the Ca2+-dependent phosphoprotein intermediate of the (Mg2+ + Ca2+)-dependent ATPase in erythrocyte membranes was investigated. In the presence of 60 microM-Ca2+ and 25 microM-MgCl2, calmodulin (0.5-1.5 microgram) did not alter the steady-state concentration of the phosphoprotein, but increased its rate of decomposition. Higher calmodulin concentrations significantly decreased the steady-state concentration of phosphoprotein. Calmodulin (0.5-1.7 microgram) increased Ca2+-transport ATPase activity by increasing the turnover rate of its phosphoprotein intermediate. Increasing the MgCl2 concentration from 25 microM to 250 microM increased the (Mg2+ + Ca2+)-dependent ATPase activity, but decreased the concentration of the phosphoprotein intermediate. Similarly to calmodulin, MgCl2 increased the turnover rate of the Ca2+-transport ATPase complex (about 3-fold). At the higher MgCl2 concentration calmodulin did not further affect the decomposition of the phosphoprotein intermediate. It was concluded that both calmodulin and MgCl2 increase the turnover of the Ca2+-pump by enhancing the decomposition of the Ca2+-dependent phosphoprotein intermediate.

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