EurekaMag
+ Translate
+ Most Popular
Gaucher's disease;thirty-two years experience at Siriraj Hospital
A study of Macrobathra Meyrick from China (Lepidoptera, Cosmopterigidae)
First occurrence in ores of tetragonal chalcocite
Effects of trace element nutrition on sleep patterns in adult women
N.Z. range management guidelines. 2. Design of grazing management systems for tussock country
A case of lipoma of the esophagus
A revision of world Acanthosomatidae (Heteroptera: Pentatomidae): keys to and descriptions of subfamilies, tribes and genera, with designation of types
Life history of the coronate scyphozoan Linuche unguiculata (Swartz, 1788)
Perceptual restoration of obliterated sounds
Mutagenicity studies on two chromium(III) coordination compounds
The formation of the skeleton. I. Growth of a long bone. 1st appearance of a center of calcification
Leucopenia and abnormal liver function in travellers on malaria chemoprophylaxis
The joint commission: four key root causes loom large in sentinel event data
Treatment of vitiligo with topical 15% lactic acid solution in combination with ultra violet-A
Behaviour of dairy cows within three hours after feed supply: I. Influence of housing type and time elapsing after feed supply
Observations of the propagation velocity and formation mechanism of burst fractures caused by gunshot
Management and control of patients with type 2 diabetes mellitus in Lebanon: results from the International Diabetes Management Practices Study (IDMPS)
The diet composition and nutritional knowledge of patients with anorexia nervosa
Physoporella croatica Herak, 1958 of the Slovak karst Anisian (Slovakia, the West Carpathians Mts.)
Bright lights, big noise. How effective are vehicle warning systems?
Ein Plesiosaurier-Rest mit Magensteinen aus mittlerem Lias von Quedlinburg
Incidence of Chlamydia trachomatis in patients with sterility
Monster soup: the microscope and Victorian fantasy
Preliminary tests with residual sprays against poultry lice
Duration of the life of plants in phylogeny

On the interrelation between calmodulin and EGTA in the regulation of the affinity to Ca2+ and the maximal activity of the erythrocyte-membrane calcium pump


On the interrelation between calmodulin and EGTA in the regulation of the affinity to Ca2+ and the maximal activity of the erythrocyte-membrane calcium pump



European Journal of Biochemistry 132(2): 315-319



ISSN/ISBN: 0014-2956

PMID: 6404633

DOI: 10.1111/j.1432-1033.1983.tb07364.x

1. Calmodulin distribution in rat erythrocytes and the interrelation between calmodulin and EGTA in regulation of the rate of 45Ca accumulation by erythrocyte-membrane inside-out vesicles were studied. 2. The total content of calmodulin in rat erythrocytes is about 24 mumol/l of cells. About 60% of calmodulin is localized in cytoplasm and 40% (10 mumol/l of cells) of calmodulin is loosely bound to membranes; after subsequent washing by hypotonic solution (membranes A) the content of membrane-bound calmodulin decreases up to 0.1 mumol/l of cells. 3. The addition of exogenous calmodulin to membranes A results in increase of the maximal activity of the Ca-pump and does not influence its affinity to Ca2+. Troponin I (30 microM) completely abolishes the calmodulin effect on the Ca-pump activity without significant alterations in its basal activity. 4. The addition of EGTA in the membrane-washing solution results in decrease of the membrane-found pool calmodulin up to 0.01 mumol/l of cells (membranes B). This procedure is accompanied by decrease of the affinity of Ca-pump to Ca2+ and does not influence its maximal rate. 5. The effect of EGTA treatment (membranes B) on the affinity of Ca-pump to Ca is abolished after addition of micromolar concentrations of calmodulin or millimolar concentration of EGTA in the incubation medium. The increase of EGTA concentration in the incubation medium results in decrease of the affinity of Ca-pump to calmodulin. 6. It is assumed that two essentially different pools of calmodulin participate in the regulation of the activity of Ca-pump. (a) The pool of calmodulin which is loosely bound to membrane (this size is dependent on calmodulin concentration in cytoplasm) determines the maximal activity of Ca-pump. The effect of this calmodulin pool is blocked by troponin I. (b) The tightly bound pool of calmodulin which is removed by EGTA treatment determines the affinity of Ca-pump to Ca. 7. In this connection the reasons for contradictory data on estimation of calmodulin effect on the kinetic parameters of plasma membrane Ca-pump are discussed.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 043818111

Download citation: RISBibTeXText

Related references

On the interrelation between calmodulin and ethylene glycol bis beta aminoethyl ether n n n' n' tetra acetic acid in the regulation of the affinity to calcium and the maximal activity of the erythrocyte membrane calcium pump. European Journal of Biochemistry 132(2): 315-320, 1983

On the mechanisms of calmodulin involvement in regulation of affinity for calcium and maximal activity of the calcium pump in erythrocyte membranes. Biokhimiya 50(12): 2056-2062, 1985

Mechanism of involvement of calmodulin in the regulation of affinity to Ca2+ and maximum activity of Ca-pump in the erythrocyte membrane. Biokhimiia 50(12): 2056-2062, 1985

Role of calcium ion in the excitability and electrogenic pump activity of the chara corallina membrane ii. effects of lanthanum egta and calmodulin antagonists on the current voltage relation. Journal of Membrane Biology 96(1): 75-84, 1987

Regulation of the calcium ion pump of sarcoplasmic reticulum: reversible inhibition by phospholamban and by the calmodulin binding domain of the plasma membrane calcium ion pump. Biochemistry 31(2): 371-376, 1992

Plasma membrane calcium pump isoform 2 has an unusually high affinity for calmodulin and calcium. Biophysical Journal 74(2 Part 2): A42, 1998

Potassium and anion transport and activity of the Na+-pump in the erythrocyte membrane: 3 different mechanisms of regulation by intracellular calcium. Biokhimiia 52(8): 1373-1386, 1987

Regulation by calmodulin of the plasticity of the calcium pump in human erythrocyte vesicles. Journal of Supramolecular Structure 9(Suppl. 4): 87, 1980

Calmodulin X (Ca2+)4 is the active calmodulin-calcium species activating the calcium-, calmodulin-dependent protein kinase of cardiac sarcoplasmic reticulum in the regulation of the calcium pump. Biochimica et Biophysica Acta 773(2): 197-206, 1984

Characterization of EGTA-washed synaptosomal membrane with emphasis on its calmodulin-binding proteins. Demonstration of possible reconstitution with added calcium/calmodulin. Biochimica et Biophysica Acta 1133(2): 193-205, 1992

Calmodulin antagonism and inhibition of erythrocyte plasma membrane Ca(2+)-pump by nifedipine, a calcium channel blocker. African Journal of Medicine and Medical Sciences 21(1): 17-21, 1992

More residues are required for full calmodulin affinity in plasma membrane calcium pump isoform 4a than in 4b. FASEB Journal 9(6): A1446, 1995

Effects of phospholamban transmembrane mutants on the calcium affinity, maximal activity, and cooperativity of the sarcoplasmic reticulum calcium pump. Biochemistry 48(39): 9287-9296, 2009

Cooperative calcium binding and calmodulin regulation in the calcium-dependent adenosine triphosphatase purified from the erythrocyte membrane. Febs Letters 189(1): 67-71, 1985

Studies of the Ca2+ transport mechanism of human erythrocyte inside-out plasma membrane vesicles. I. Regulation of the Ca2+ pump by calmodulin. Journal of Biological Chemistry 256(1): 409-414, 1981