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Peluffo RD, Hernández JA. The Na +,K +-ATPase and its stoichiometric ratio: some thermodynamic speculations. Biophys Rev 2023; 15:539-552. [PMID: 37681108 PMCID: PMC10480117 DOI: 10.1007/s12551-023-01082-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 06/18/2023] [Indexed: 09/09/2023] Open
Abstract
Almost seventy years after its discovery, the sodium-potassium adenosine triphosphatase (the sodium pump) located in the cell plasma membrane remains a source of novel mechanistic and physiologic findings. A noteworthy feature of this enzyme/transporter is its robust stoichiometric ratio under physiological conditions: it sequentially counter-transports three sodium ions and two potassium ions against their electrochemical potential gradients per each hydrolyzed ATP molecule. Here we summarize some present knowledge about the sodium pump and its physiological roles, and speculate whether energetic constraints may have played a role in the evolutionary selection of its characteristic stoichiometric ratio.
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Affiliation(s)
- R. Daniel Peluffo
- Group of Biophysical Chemistry, Department of Biological Sciences, CENUR Litoral Norte, Universidad de La República, Rivera 1350, CP: 50000 Salto, Uruguay
| | - Julio A. Hernández
- Biophysics and Systems Biology Section, Department of Cell and Molecular Biology, Facultad de Ciencias, Universidad de La República, Iguá 4225, CP: 11400 Montevideo, Uruguay
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2
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Park MS, Lee EY, Lee NS, Waniewski J, Lindholm B, Lee HB. The Effects of Ouabain and Potassium on Peritoneal Fluid and Solute Transport Characteristics. Perit Dial Int 2020. [DOI: 10.1177/089686089801800409] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BackgroundWe reported anomalous transport characteristics of potassium during experimental peritoneal dialysis in rats and suggested that mechanisms of peritoneal potassium transport could be other than simple passive transport. Intracellular transport of potassium in cultured human mesothelial cells was reported to be regulated by three different pathways, such as channels blocked by ouabain, channels blocked by furosemide, and other.ObjectiveTo investigate the effect of ouabain on peritoneal potassium and water transport characteristics.MethodsA single 4-hour peritoneal dwell was performed in 28 5prague-Dawley rats. To minimize the diffusive transport of potassium, 4.5 mmol/L of KCI was added into conventional dialysis solution with 3.86% glucose [acidic peritoneal dialysis solution (APD)]. To evaluate the effect of the pH of dialysis solution on the transport of potassium and water, 4 mmol/L of NaOH was added into the potassium -containing study solutions [neutral peritoneal dialysis solution (NPD)]. To evaluate the effect of a potassium channel blocker on peritoneal potassium transport ATPase sensitive Na+-K+-transport inhibitor, ouabain (10–5 mmol/L) was added to dialysis solutions immediately before the dwell study in eight rats with APD (APD-O) and six rats with NPD (NPD-O). Ouabain was not added in eight and six rats with APD and NPD (APD-C and NPD-C, respectively). They were used as control. Infusion volume was 30 mL. The intraperitoneal volume (V D) was estimated by using a volume marker dilution method with corrections for the elimination of volume marker, radioiodinated human serum albumin (RI5A), from the peritoneal cavity (KE). The diffusive mass transport coefficient (KBD) and sieving coefficient (5) were estimated using the modified Babb-Randerson-Farrell model.ResultsVD was significantly higher (p < 0.05 from 90 min to 240 min) and KE (0.027 ± 0.018 mL/min for APD-O, 0.026 ± 0.017 mL/min for NPD-O, and 0.030 ± 0.022 mL/min for NPD-C, vs 0.058 ± 0.030 mL/min for APD-C, p < 0.05 for each) significantly lower during dialysis with APD -O, NPD -O, and NPD-C than with APD-C. The intraperitoneal glucose expressed as a percentage of the initial amount was significantly higher with APD-O, NPD-C, and NPD-Q than with APD-C (p < 0.05 from 90 min to 240 min). KBD for sodium was higher during dialysis with ouabain than without ouabain, while KBD for urea, glucose, and potassium, and 5 for urea, glucose, sodium, and potassium did not differ between the four groups.ConclusionsThe physiologic potassium concentration in neutral dialysis solutions and the use of ouabain decreased the intraperitoneal fluid absorption. The diffusive transport coefficient and sieving coefficient for potassium did not differ, while the diffusive transport coefficient for sodium increased during use of ouabain.
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Affiliation(s)
- Min Sun Park
- Hyonam Kidney Laboratory; Soon Chun Hyang University; Seoul, Korea
| | - Eun Young Lee
- Hyonam Kidney Laboratory; Soon Chun Hyang University; Seoul, Korea
| | - Nam Soo Lee
- Hyonam Kidney Laboratory; Soon Chun Hyang University; Seoul, Korea
| | - Jacek Waniewski
- Division of Baxter Novum, Department of Clinical Sciences, Karolinska Institute, Stockholm, Sweden
- Department of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Bengt Lindholm
- Division of Baxter Novum, Department of Clinical Sciences, Karolinska Institute, Stockholm, Sweden
| | - Hi Bahl Lee
- Hyonam Kidney Laboratory; Soon Chun Hyang University; Seoul, Korea
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Abstract
Reconstitution of P-type ATPases in unilamellar liposomes is a useful technique to study functional properties of these active ion transporters. Experiments with such liposomes provide an easy access to substrate-binding affinities of the ion pumps as well as to the lipid and temperature dependence of the pump current. Here, we describe two reconstitution methods by dialysis and the use of potential-sensitive fluorescence dyes to study transport properties of two P-type ATPases, the Na,K-ATPase from rabbit kidney and the K(+)-transporting KdpFABC complex from E. coli. Several techniques are introduced how the measured fluorescence signals may be analyzed to gain information on properties of the ion pumps.
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Affiliation(s)
- Hans-Jürgen Apell
- Department of Biology, University of Konstanz, 635, Universitätsstr. 10, Konstanz, 78464, Germany.
| | - Bojana Damnjanovic
- Department of Biology, University of Konstanz, 635, Universitätsstr. 10, Konstanz, 78464, Germany
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Lingwood D, Harauz G, Ballantyne JS. Decoupling the Na+–K+–ATPase in vivo: A possible new role in the gills of freshwater fishes. Comp Biochem Physiol A Mol Integr Physiol 2006; 144:451-7. [PMID: 16730202 DOI: 10.1016/j.cbpa.2006.03.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Revised: 03/28/2006] [Accepted: 03/28/2006] [Indexed: 11/16/2022]
Abstract
The literature suggests that when Na(+)-K(+)-ATPase has reduced access to its glycosphingolipid cofactor sulfogalactosyl ceramide (SGC), it is converted to a Na(+) uniporter. We recently showed that such segregation can occur within a single membrane when Na(+)-K(+)-ATPase is excluded from membrane microdomains or 'lipid rafts' enriched in SGC (D. Lingwood, G. Harauz, J.S. Ballantyne, J. Biol. Chem. 280, 36545-36550). Specifically we demonstrated that Na(+)-K(+)-ATPase localizes to SGC-enriched rafts in the gill basolateral membrane (BLM) of rainbow trout exposed to seawater (SW) but not freshwater (FW). We therefore proposed that since the freshwater gill Na(+)-K(+)-ATPase was separated from BLM SGC it should also transport Na(+) only, suggesting a new role for the pump in this epithelium. In this paper we discuss the biochemical evidence for SGC-based modulation of transport stoichiometry and highlight how a unique asparagine-lysine substitution in the FW pump isoform and FW gill transport energetics gear the Na(+)-K(+)-ATPase to perform Na(+) uniport.
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Affiliation(s)
- D Lingwood
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada N1G 2W1.
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5
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Koepsell H. Methodological aspects of purification and reconstitution of transport proteins from mammalian plasma membranes. Rev Physiol Biochem Pharmacol 2006; 104:65-137. [PMID: 2940665 DOI: 10.1007/bfb0031013] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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6
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Apell HJ. Structure-function relationship in P-type ATPases--a biophysical approach. Rev Physiol Biochem Pharmacol 2004; 150:1-35. [PMID: 12811587 DOI: 10.1007/s10254-003-0018-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
P-type ATPases are a large family of membrane proteins that perform active ion transport across biological membranes. In these proteins the energy-providing ATP hydrolysis is coupled to ion-transport that builds up or maintains the electrochemical potential gradients of one or two ion species across the membrane. P-type ATPases are found in virtually all eukaryotic cells and also in bacteria, and they are transporters of a broad variety of ions. So far, a crystal structure with atomic resolution is available only for one species, the SR Ca-ATPase. However, biochemical and biophysical studies provide an abundance of details on the function of this class of ion pumps. The aim of this review is to summarize the results of preferentially biophysical investigations of the three best-studied ion pumps, the Na,K-ATPase, the gastric H,K-ATPase, and the SR Ca-ATPase, and to compare functional properties to recent structural insights with the aim of contributing to the understanding of their structure-function relationship.
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Affiliation(s)
- H-J Apell
- Department of Biology, University of Konstanz, Fach M635, 78457 Konstanz, Germany.
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7
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Burckhardt G, Greger R. Principles of Electrolyte Transport Across Plasma Membranes of Renal Tubular Cells. Compr Physiol 1992. [DOI: 10.1002/cphy.cp080114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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8
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Cornelius F. Functional reconstitution of the sodium pump. Kinetics of exchange reactions performed by reconstituted Na/K-ATPase. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1071:19-66. [PMID: 1848452 DOI: 10.1016/0304-4157(91)90011-k] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- F Cornelius
- Institute of Biophysics, University of Aarhus, Denmark
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9
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Villalobo A. Reconstitution of ion-motive transport ATPases in artificial lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1017:1-48. [PMID: 1693288 DOI: 10.1016/0005-2728(90)90176-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- A Villalobo
- Instituto de Investigaciones Biomédicas, C.S.I.C., Madrid, Spain
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10
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Apell HJ, Häring V, Roudna M. Na,K-ATPase in artificial lipid vesicles. Comparison of Na,K and Na-only pumping mode. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1023:81-90. [PMID: 2156565 DOI: 10.1016/0005-2736(90)90012-d] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Na,K-ATPase from rabbit kidney outer medulla was reconstituted in large unilamellar lipid vesicles by detergent dialysis. Vesicles prepared in the presence or absence of potassium allowed to study two different transport modes: the (physiological) Na,K-mode in buffers containing Na+ and K+ and the Na-only mode in buffers containing Na+ but no K+. The ATP hydrolysis activity was obtained by determination of the liberated inorganic phosphate, Pi, and the inward directed Na+ flux was measured by 22Na-tracer flux. Electrogenic transport properties were studied using the membrane potential sensitive fluorescence-dye oxonol VI. The ratio upsilon(Na,K)/upsilon(Na) of the turnover rates in the Na,K-mode and in the Na-only mode is 6.6 +/- 2.0 under otherwise identical conditions and nonlimiting Na+ concentrations. Strong evidence is found that the Na-only mode exhibits a stoichiometry of 3Na+cyt/2Na+ext/1ATP, i.e. the extracellular (= intravesicular) Na+ has a potassium-like effect. In the Na-only mode one high-affinity binding side for ATP (KM congruent to 50 nM) was found, in the Na,K-mode a high- and low-affinity binding side with equilibrium dissociation constants, KM, of 60 nM and 13 microM, respectively. The sensitivity against the noncompetitively inhibiting ADP (KI = 6 microM) is higher by a factor of 20 in the Na-only mode compared to the Na,K-mode. From the temperature dependence of the pumping activity in both transport modes, activation energies of 160 kJ/mol for the Na,K-mode and 110 kJ/mol for the Na-only mode were determined.
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Affiliation(s)
- H J Apell
- Department of Biology, University of Konstanz, F.R.G
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11
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Affiliation(s)
- H J Apell
- Department of Biology, University of Konstanz, Federal Republic of Germany
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12
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Clarke RJ, Apell HJ, Läuger P. Pump current and Na+/K+ coupling ratio of Na+/K+-ATPase in reconstituted lipid vesicles. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 981:326-36. [PMID: 2543461 DOI: 10.1016/0005-2736(89)90044-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A method is described for studying the coupling ratio of the Na+/K+ pump, i.e., the ratio of pump-mediated fluxes of Na+ and K+, in a reconstituted system. The method is based on the comparison of the pump-generated current with the rate of K+ transport. Na+/K+-ATPase from kidney is incorporated into the membrane of artificial lipid vesicles; ATPase molecules with outward-oriented ATP-binding site are activated by addition of ATP to the medium. Using oxonol VI as a potential-sensitive dye for measuring transmembrane voltage, the pump current is determined from the change of voltage with time t. In a second set of experiments, the membrane is made selectively K+-permeable by addition of valinomycin, so that the membrane voltage U is equal to the Nernst potential of K+. Under this condition, dU/dt reflects the change of intravesicular K+ concentration and thus the flux of K+. Values of the Na+/K+ coupling ratio determined in this way are close to 1.5 in the experimental range (10-75 mM) of extravesicular (cytoplasmic) Na+ concentrations.
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Affiliation(s)
- R J Clarke
- Department of Biology, University of Konstanz, F.R.G
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13
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Chapter 13 Sodium Pump Current in Renal Tubular Cells. ACTA ACUST UNITED AC 1989. [DOI: 10.1016/s0070-2161(08)60017-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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15
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Goldin SM, Forgac M, Chin G. Reconstitution of Na,K-pump activity by cholate dialysis: sidedness and stoichiometry. Methods Enzymol 1988; 156:127-40. [PMID: 2835599 DOI: 10.1016/0076-6879(88)56016-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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16
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Cornelius F. Incorporation of C12E8-solubilized Na+,K+-ATPase into liposomes: determination of sidedness and orientation. Methods Enzymol 1988; 156:156-67. [PMID: 2835601 DOI: 10.1016/0076-6879(88)56018-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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17
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Hokin LE, Dixon JF. Reconstitution of the Na,K-pump by freeze-thaw sonication: estimation of coupling ratio and electrogenicity. Methods Enzymol 1988; 156:141-55. [PMID: 2835600 DOI: 10.1016/0076-6879(88)56017-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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18
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Avison MJ, Gullans SR, Ogino T, Giebisch G, Shulman RG. Measurement of Na+-K+ coupling ratio of Na+-K+-ATPase in rabbit proximal tubules. THE AMERICAN JOURNAL OF PHYSIOLOGY 1987; 253:C126-36. [PMID: 2440310 DOI: 10.1152/ajpcell.1987.253.1.c126] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A combination of 23Na nuclear magnetic resonance (NMR) spectroscopy and a K+-selective electrode was used to make simultaneous measurements of net Na+ and K+ fluxes across plasma membranes of rabbit renal proximal tubules after an abrupt stimulation of Na+-K+-ATPase. After a step in extracellular K+ concentration ([K+]o) from low to higher concentration (0.1-0.3 mM to 0.5-5.2 mM) at 25 degrees C, net extrusion of Na+ and uptake of K+ were observed. These fluxes were completely inhibited by ouabain (10(-3) M). Because initial rates of K+ uptake in presence or absence of Ba2+ (a known inhibitor of plasma membrane K+ conductance) were indistinguishable, net K+ flux was virtually unidirectional. Because suspension buffers contained neither glucose nor amino acids and the ratio of net Na+ and K+ fluxes (JNa and JK, respectively) was constant over a wide range of transmembrane Na+ gradients and absolute values of the JNa and JK, it is likely that changes in electrogenic or passive net fluxes across plasma membranes were insignificant in the first 30-45 s after the [K+]o step. Thus the ratio of these initial net Na+ and K+ fluxes corresponds closely to the Na+-K+ coupling ratio of the Na+-K+-ATPase. In 12 experiments, the measured Na+-K+-ATPase coupling ratio was 1.54 +/- 0.07 (SE). The coupling ratio was constant over a wide range of intracellular Na+ content, intracellular sodium concentration, [K+]o and transmembrane Na+ gradient. The coupling ratio also remained constant over an eightfold range of Na+-K+-ATPase rates.
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Apell HJ, Marcus MM. (Na+ + K+)-ATPase in artificial lipid vesicles: influence of the concentration of mono- and divalent cations on the pumping rate. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 862:254-64. [PMID: 3022809 DOI: 10.1016/0005-2736(86)90226-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
(Na+ + K+)-ATPase from kidney outer medulla was incorporated into artificial dioleoylphosphatidylcholine vesicles. Transport activity was induced by adding ATP to the external medium. A voltage-sensitive dye was used to detect the ATP-driven potassium extrusion in the presence of valinomycin. The observed substrate-protein interactions of the reconstituted (Na+ + K+)-ATPase largely agree with that from native tissues. An agreement between ATP hydrolysis and transport activity is given for concentration dependences of sodium, potassium, magnesium and calcium ions. The only significant deviations were observed in the influence of pH. Protons were found to have different influence on transport, enzymatic activity and phosphorylation of the enzyme. The transport studies showed a twofold interaction of protons with the protein: competition with sodium at the cytoplasmic ion binding sites, a non competitive inhibition of transport which is not correlated with protein phosphorylation.
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Apell HJ, Nelson MT, Marcus MM, Läuger P. Effects of the ATP, ADP and inorganic phosphate on the transport rate of the Na+,K+-pump. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 857:105-15. [PMID: 3008841 DOI: 10.1016/0005-2736(86)90103-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
(Na+ + K+)-ATPase from kidney outer medulla was incorporated into artificial dioleoylphosphatidylcholine vesicles. In the reconstituted system the pump can be activated by adding ATP to the external medium. ATP-driven potassium extrusion by the Na+,K+-pump was studied using a voltage-sensitive dye in the presence of valinomycin. ADP strongly reduced the turnover rate of the pump with a concentration for half-maximal inhibition of cD,1/2 = 0.1 mM. cD,1/2 was found to be virtually independent of ATP concentration, indicating that the inhibition is non-competitive with respect to ATP. The non-competitive inhibition by ADP can be explained on the basis of the Post-Albers reaction cycle of the Na+,K+-pump, assuming that the main action of ADP is the reversal of the phosphorylation step. A similar 'product inhibition' was observed with inorganic phosphate, but at much higher concentrations (cP,1/2 = 14 mM).
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Marcus MM, Apell HJ, Roudna M, Schwendener RA, Weder HG, Läuger P. (Na+ + K+)-ATPase in artificial lipid vesicles: influence of lipid structure on pumping rate. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 854:270-8. [PMID: 3002468 DOI: 10.1016/0005-2736(86)90120-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
(Na+ + K+)-ATPase from kidney outer medulla was incorporated into tightly-sealed, single-shelled lipid vesicles by a detergent-dialysis procedure. The rate of ATP-driven potassium extrusion from vesicles formed from different phosphatidylcholines (PC) was measured optically, using a voltage-sensitive dye in the presence of valinomycin. High transport rates were observed for di(18:1)PC, di(20:1)PC and di(22:1)PC, whereas vesicles formed from di(14:1)PC and di(16:1)PC were virtually inactive. The variation of pumping activity with lipid structure mainly results from differences in the amount of enzyme incorporated with the correct orientation into the vesicle membrane, and to a lesser extent from lipid-dependent variations of the intrinsic turnover rate of the enzyme. The activation energy of ion transport decreases in the order di(16:1)PC, di(18:1)PC, di(20:1)PC approximately equal to di(22:1)PC.
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Anner BM. Interaction of (Na+ + K+)-ATPase with artificial membranes. I. Formation and structure of (Na+ + K+)-ATPase-liposomes. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 822:319-34. [PMID: 2998473 DOI: 10.1016/0304-4157(85)90013-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Anner BM. Interaction of (Na+ + K+)-ATPase with artificial membranes. II. Expression of partial transport reactions. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 822:335-53. [PMID: 2415163 DOI: 10.1016/0304-4157(85)90014-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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25
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Läuger P. Mechanismen des biologischen Ionentransports – Carrier, Kanäle und Pumpen in künstlichen Lipidmembranen. Angew Chem Int Ed Engl 1985. [DOI: 10.1002/ange.19850971107] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Doonan B. Model of anion and monovalent cation transport as neutral ion pairs through lipophilic water channels of the Na,K ATPase complex. Med Hypotheses 1985; 16:265-77. [PMID: 2582229 DOI: 10.1016/0306-9877(85)90009-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A model of anion and monovalent cation transport through a lipophilic water channel of the Na,K ATPase complex is presented. Literature data for the Na,K ATPase cation binding sites are combined with data for the anion binding sites of Band 3 to obtain adjacent cation and anion combining sites at the inner and outer channel mouths. Cations and anions form neutral ion pairs or undissociated acids at these sites and then partition much more favorably into lipophilic channel water, passing through the channel in diffusive fashion. Cation movements in an "uphill" direction occur without an enzyme translocating moiety and its specific energetic requirement. The pertinent factors are the exclusion of unpaired cations by the tight channel and the site selectivity or pickup ratios for Na/K at each side which dominate over bulk and transmembrane concentration ratios. ATP hydrolysis provides phosphate for ion pairing.
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Apell HJ, Marcus MM, Anner BM, Oetliker H, Läuger P. Optical study of active ion transport in lipid vesicles containing reconstituted Na,K-ATPase. J Membr Biol 1985; 85:49-63. [PMID: 2991528 DOI: 10.1007/bf01872005] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A fluorescence method is described for the measurement of ATP-driven ion fluxes in lipid vesicles containing purified Na,K-ATPase. The membrane voltage of enzyme containing vesicles was measured by using a voltage-sensitive indocyanine dye. By addition of valinomycin the vesicle membrane is made selectively permeable to K+ so that the membrane voltage approaches the Nernst potential for K+. With constant external K+ concentration, the time course of internal K+ concentration can be continuously measured as change of the fluorescence signal after activation of the pump. The optical method has a higher time resolution than tracer-flux experiments and allows an accurate determination of initial flux rates. From the temperature dependence of active K+ transport its activation energy was determined to be 115 kJ/mol. ATP-stimulated electrogenic pumping can be measured as fast fluorescence change when the membrane conductance is low (i.e., at low or zero valinomycin concentration). In accordance with expectation, the amplitude of the fast signal change increases with decreasing passive ion permeability of the vesicle membrane. The resolution of the charge movement is so high that a few pump turnovers can be easily detected.
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29
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Yoda A, Clark AW, Yoda S. Reconstitution of (Na+ + K+)-ATPase proteoliposomes having the same turnover rate as the membranous enzyme. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 778:332-40. [PMID: 6093885 DOI: 10.1016/0005-2736(84)90377-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Membranous (Na+ + K+)-ATPase from the electric eel was solubilized with 3-[3-cholamidopropyl)-dimethylammonio)-1-propanesulfonate (Chaps). 50 to 70% of the solubilized enzyme was reconstituted in egg phospholipid liposomes containing cholesterol by using Chaps. The obtained proteoliposomes consisted of large vesicles with a diameter of 134 +/- 24 nm as the major component, and their protein/lipid ratio was 1.25 +/- 0.07 g protein/mol phospholipid. The intravesicular volume of these proteoliposomes is too small to consistently sustain the intravesicular concentrations of ligands, especially K+, during the assay. The decrease in K+ concentration was cancelled by the addition of 20 microM valinomycin in the assay medium. The low value of the protein/lipid ratio suggests that these proteoliposomes contain one Na+/K+-pump particle with a molecular mass of 280 kDa per one vesicle as the major component. In these proteoliposomes, the specific activity of the (Na+ + K+)-ATPase reaction was 10 mumol Pi/mg protein per min, and the turnover rate of the ATP-hydrolysis was 3500 min-1, the same as the original enzyme under the same assay condition. The ratio of transported Na+ to hydrolyzed ATP was 3, the same as that in the red cell. The proteoliposomes could be disintegrated by 40-50 mM Chaps without any significant inactivation. This disintegration of proteoliposomes nearly tripled the ATPase activity compared to the original ones and doubled the specific ATPase activity compared to the membranous enzyme, but the turnover rate was the same as the original proteoliposomes and the membranous enzyme. This disintegration of proteoliposomes by Chaps suggests the selective incorporation of the (Na+ + K+)-ATPase particle into the liposomes and the asymmetric orientation of the (Na+ + K+)-ATPase particle in the vesicle.
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Reinhardt R, Lindemann B, Anner BM. Leakage-channel conductance of single (Na+ + K+)-ATPase molecules incorporated into planar bilayers by fusion of liposomes. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 774:147-50. [PMID: 6329293 DOI: 10.1016/0005-2736(84)90285-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
By fusing liposomes which contain in the mean only one pump unit (one intramembranous particle) to planar bilayers, and provoking the ouabain-blockable leakage conductance by the presence of n-decane, the predominant unit leakage conductance associated with one pump unit was estimated to be 40-50 pS, indicating the channel nature of the leakage pathway.
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Anner BM, Robertson JD, Ting-Beall HP. Characterization of (Na+ + K+)-ATPase liposomes. I. Effect of enzyme concentration and modification on liposome size, intramembrane particle formation and Na+,K+-transport. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 773:253-61. [PMID: 6329284 DOI: 10.1016/0005-2736(84)90089-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Rabbit renal (Na+ + K+)-ATPase (EC 3.6.1.3) was purified and incorporated into phosphatidylcholine liposomes. Freeze-fracture analysis of the reconstituted system reveals intramembrane particles formed by (Na+ + K+)-ATPase molecules which are randomly distributed on concave and convex fracture faces. The reconstituted (Na+ + K+)-ATPase performs active Na+,K+-transport. The distribution of particles as well as the rate of active transport are directly proportional to the (Na+ + K+)-ATPase protein concentration used for reconstitution, while the total amount of sodium and potassium ions exchanged by ATP per volume vesicle suspension reaches maximum when each vesicle contains on the average more than two particles. (Na+ + K+)-ATPase pretreated with ouabain or vanadate yields the same particle density and vesicle size as control enzyme. However, detergent-denatured enzyme loses its ability to form intramembrane particles or to increase the vesicle size indicating that the lipids surrounding the protein part of the molecule are essential for the reconstitution process. The vesicle diameter increases as a function of the number of particles per vesicle. Histograms of the size distribution become wider with increasing intramembrane particle density and tend to show more than one maximum.
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Cornelius F, Skou JC. Reconstitution of (Na+ + K+)-ATPase into phospholipid vesicles with full recovery of its specific activity. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 772:357-73. [PMID: 6326830 DOI: 10.1016/0005-2736(84)90153-6] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
(Na+ + K+)-ATPase from rectal glands of the spiny dogfish has been reconstituted into phospholipid vesicles. The nonionic detergent octaethyleneglycoldodecyl monoether ( C12E8 ) is used to dissolve both the enzyme and the lipids and reconstitution is accomplished by subsequent removal of the detergent by adsorption to polystyrene beads. About 60% of the enzyme incorporates in the right-side-out orientation (r/o). The fraction of molecules in the inside-out orientation (i/o) increases from about 10% to about 30% with a parallel decrease in the fraction of 'non-oriented' (n-o) molecules (both sides exposed) when the protein/lipid ratio decreases from 1:10 to 1:75. The orientation of enzyme molecules detected from vanadate binding is the same as measured from activity, i.e., the turnover of the enzyme molecule in the different orientations is the same. The recovery of the specific activity of the incorporated enzyme increases with an increase in the protein/lipid ratio and is 100% with a protein/lipid ratio of about 1:20 or higher. Full recovery is only obtained provided a proper lipid composition is chosen which includes both negatively charged phospholipids, preferably phosphatidylinositol, and cholesterol. The ATP-dependent, K+-stimulated Na+-influx is found to be about 35 mumol Na+ per mg (i/o)-protein per min at 22 degrees C in 1:10 protein/lipid liposomes. The specific activity corresponds to 3 Na+ transported per ATP molecule hydrolyzed.
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Na and K Fluxes Mediated by ATP-Free and ATP-Activated Na,K-ATPase in Liposomes. ACTA ACUST UNITED AC 1983. [DOI: 10.1016/s0070-2161(08)60617-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Eytan GD. Use of liposomes for reconstitution of biological functions. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 694:185-202. [PMID: 6753932 DOI: 10.1016/0304-4157(82)90024-7] [Citation(s) in RCA: 194] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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35
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Ross MD, Ernst SA, Kerr TP. Possible functional roles of Na+,K+-ATPase in the inner ear and their relevance to Ménière's disease. Am J Otolaryngol 1982; 3:353-60. [PMID: 6293330 DOI: 10.1016/s0196-0709(82)80010-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
This article reviews the functions of the enzyme Na+,K+-ATPase in epithelial tissues and discusses early and recent biochemical, physiologic and morphologic studies of the enzyme in the inner ear. The purpose of the investigation was to learn whether a relationship between perturbations in activity of the enzyme and Ménière's disease is possible. It is concluded that the preponderance of the evidence indicates that Na+,K+-ATPase plays a role in regulating ion transport into the scala media, but that the significance of the distribution of the enzyme along only one cell type (the marginal) in the functional chains of cells of the outer cochlear wall needs further study. The possible vasoconstrictive effects of ouabain perfusions employed by some investigators must also be taken into account. Recent cytochemical and autoradiographic studies have demonstrated high levels of Na+, K+-ATPase on cochlear nerve fibers, especially near the foramina nervosa and within the organ of Corti. Thus, perturbations in Na+,K+-ATPase activity in the inner ear not only could affect certain aspects of fluid balance, but also could account for the sensory disturbances experienced by patients who have Ménière's disease.
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Jørgensen PL. Mechanism of the Na+, K+ pump. Protein structure and conformations of the pure (Na+ +K+)-ATPase. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 694:27-68. [PMID: 6289898 DOI: 10.1016/0304-4157(82)90013-2] [Citation(s) in RCA: 443] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Anner BM, Moosmayer M. Preparation of Na,K-ATPase-containing liposomes with predictable transport properties by a procedure relating the Na,K-transport capacity to the ATPase activity. JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS 1982; 5:299-306. [PMID: 6279719 DOI: 10.1016/0165-022x(82)90001-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A microprocedure for the preparation of Na,K-ATPase-containing liposomes with a minimal starting material (200 microgram) of purified Na,K-ATPase is presented. Phosphatidylcholine is added gradually to cholate-solubilized Na,K-ATPase of various concentrations and the lipid-induced decrease in enzyme activity is monitored. After removal of the detergent by dialysis, the transport parameters of the resulting Na,K-ATPase-liposomes are established by a microassay. By relating the transport properties to the Na,K-ATPase activity preset before dialysis, a procedure is developed which allows to prepare standardized Na,K-ATPase-liposomes with predictable transport properties.
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Reconstitution of a sodium pump on lipid vesicles. NEUROPHYSIOLOGY+ 1982. [DOI: 10.1007/bf01058668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Kracke GR, O'Neal SG, Chacko GK. Partial purification and characterization of (Na+ + K+)-ATPase from garfish olfactory nerve axon plasma membrane. J Membr Biol 1981; 63:147-56. [PMID: 6273569 DOI: 10.1007/bf01969455] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The (Na+ + K+)-ATPase of garfish olfactory nerve axon plasma membrane was purified about sixfold by treatment of the membrane with sodium dodecyl sulfate followed by sucrose density gradient centrifugation. The estimated molecular weights of the two major polypeptide components of the enzyme preparation on sodium dodecyl sulfate gels were 110,000 and 42,000 daltons, which were different from those of the corresponding peptides of rabbit kidney (Na+ + K+)-ATPase. No carbohydrate was detected in the 42,000-dalton component either by the periodic acid-Schiff reagent or by the more sensitive concanavalin A-peroxidase staining procedure. The molecular properties of the garfish (Na+ + K+)-ATPase, such as the Km for ATP, pH optimum, energies of activation, Na and K ion dependence and vanadium inhibition, were, however, similar to those of the kidney enzyme. The partially purified garfish (Na+ + K+)-ATPase was reconstituted into phospholipid vesicles by a freeze-thaw-sonication procedure. The reconstituted enzyme was found to catalyze a time and ATP dependent 22Na+ transport. The ratio of 22Na+ pumped to ATP hydrolyzed was about 1; under the same reconstitution and assay conditions, eel electroplax (Na+ + K+)-ATPase, however, gave a 22Na+ pumped to ATP hydrolyzed ratio of nearly 3.
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Anner BM. A transport model for the (Na+/K+)ATPase in liposomes including the (Na+/K+)-channel function. Biosci Rep 1981; 1:555-60. [PMID: 6271285 DOI: 10.1007/bf01116304] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
(Na+/K+)ATPase liposomes of various degrees of reconstitution are formed by varying the amount of phosphatidylcholine added to the soluble (Na+/K+)ATPase before vesicles are formed by cholate removal. In the presence of ATP, the reconstituted sodium pump effectuates (Na+/K+) antiport. In the absence of ATP, the reconstituted sodium pump forms a (Na+/K+) channel. The stable plateaus formed by (1) the active Na+ transport, (2) the active K+ transport, (3) the 'passive' Na+ flux, and (4) the 'passive' K+ flux are determined in the optimally and the partially reconstituted liposomes. The activities of all four vectorial functions vary in a tightly correlated fashion, suggesting that they are mediated by the same transport-active configuration of (Na+/K+)ATPase. A transport model which includes the active and the passive (Na+/K+) fluxes mediated by the sodium pump in liposomes is outlined.
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Karlish SJ, Pick U. Sidedness of the effects of sodium and potassium ions on the conformational state of the sodium-potassium pump. J Physiol 1981; 312:505-29. [PMID: 6267267 PMCID: PMC1275566 DOI: 10.1113/jphysiol.1981.sp013641] [Citation(s) in RCA: 136] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
1. (Na,K)ATPase from kidney membranes has been reconstituted into proteoliposomes following solubilization in cholate, by the freeze-thaw sonication procedure described by Kasahara & Hinkle (1977). The method is rapid and convenient.2. Upon addition of ATP to the exterior medium the reconstituted vesicles sustain high rates of active (22)Na uptake and (86)Rb efflux with many properties similar to those of the Na/K pump in well characterized cells such as erythrocytes.3. Observations on both active and passive transport of (22) Na and (86)Rb indicate that the vesicle population is heterogeneous; about 40 per cent contain Na/K pumps and the remainder seem to be plain lipid vesicles.4. The major Na(+)- or K(+)-stabilized non-phosphorylated conformational forms of the (Na, K)ATPase, E(1). Na and E(2). (K) respectively, have been investigated in the proteoliposomes, with particular regard to sidedness of the actions of Na(+) and K(+).5. Tryptic digestion of the vesicles reveals the Na(+)- and K(+)-stabilized conformations E(1). Na and E(2). (K) as characterized originally for purified (Na, K)ATPase (Jørgensen, 1975). Controlled trypsinolysis of Tris(+)-loaded vesicles in a Na(+)-or K(+)-containing medium leads to typical biphasic (Na(+)) or simple exponential (K(+)) time courses respectively, for loss of ATP-dependent (22)Na uptake (assayed subsequent to the tryptic digestion in the presence of inophores valinomycin plus FCCP). Tryptic digestion of K(+)- or Rb(+)- or Tris(+)-loaded vesicles suspended in a Na(+) medium results only in the biphasic (E(1). Na) pattern of loss of ATP-dependent (22)Na uptake.6. ATP-dependent (22)Na uptake and (86)Rb efflux are reduced by about the same extent following a short tryptic digestion in a Na(+)-containing medium.7. Vanadate ions inhibit ATP-dependent (22)Na uptake into the vesicles, at low concentrations (K(0.5) approximately 2 x 10(-7)m), following pre-incubation together with Mg(2+) and K(+) ions. K(+) ions in the medium are effective, K(+) ions within the vesicle are not. Na(+) ions in the medium prevent inhibition by vanadate+Mg(2+) but do not reverse inhibition in vesicles pre-incubated with vanadate, Mg(2+) and K(+) ions.8. The results show that the conformational forms E(1). Na and E(2). (K) are stabilized by Na(+) or K(+) ions respectively, bound to sites on the Na/K pump normally facing the cytoplasm. The significance of this finding is discussed in relation to the cation transport function of the pump.
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Skriver E, Maunsbach AB, Jørgensen PL. Ultrastructure of Na,K-transport vesicles reconstituted with purified renal Na,K-ATPase. J Cell Biol 1980; 86:746-54. [PMID: 6251096 PMCID: PMC2110685 DOI: 10.1083/jcb.86.3.746] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
To study the size and structure of the Na,K-pump molecule, the ultrastructure of phospholipid vesicles was examined after incorporation of purified Na,K-ATPase which catalyzes active coupled transport of Na+ and K+ in a ratio close to 3Na/2K. The vesicles were analyzed by thin sectioning and freeze-fracture electron microscopy after reconstitution with different ratios of Na,K-ATPase protein to lipid, and the ultrastructural observations were correlated to the cation transport capacity. The purified Na,K-ATPase reconstituted with phospholipids to form a very uniform population of vesicles. Thin sections of preparations fixed with glutaraldehyde and osmium tetroxide showed vesicles limited by a single membrane which in samples stained with tannic acid appeared triple-layered with a thickness of 70 A. Also, freeze-fracture electron microscopy demonstrated uniform vesicles with diameters in the range of 700-1,100 A and an average value close to 900 A. The vesicle diameter was independent of the amount of protein used for reconstitution. Intramembrane particles appeared only in the vesicle membrane after introduction of Na,K-ATPase and the frequency of intramembrane particles was proportional to the amount of Na,K-ATPase protein used in the reconstitution. The particles were evenly distributed on the inner and the outer leaflet of the vesicle membrane. The diameter of the particles was 90 A and similar to our previous values for the diameter of intramembrane particles in the purified Na,K-ATPase. The capacity for active cation transport in the reconstituted vesicles was proportional to the frequency of intramembrane particles over a range of 0.2-16 particles per vesicle. The data therefore show that active coupled Na,K transport can be carried out by units of Na,K-ATPase which appear as single intramembrane particles with diameters close fo 90 A in the freeze-fracture micrographs.
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Murer H, Kinne R. The use of isolated membrane vesicles to study epithelial transport processes. J Membr Biol 1980; 55:81-95. [PMID: 6997489 DOI: 10.1007/bf01871151] [Citation(s) in RCA: 233] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Epithelia are multicompartment and multicomponent systems performing transcellular and paracellular transport in a very complex manner. One way to get a deeper understanding of the function of such a complex system is to dissect it into the single components and then, after having defined the components under well-controlled conditions, to try to describe the behavior of the whole system on the basis of the properties of the single components. This article deals with the analysis of isolated plasma membranes derived from the luminal and contraluminal face of epithelial cells, predominantly renal proximal tubular and small intestinal cells. It is aimed to give an overview of methods used to isolate and separate plasma membranes, to study their transport properties as membrane vesicles, and also to address the question of how information gained with the isolated membranes corresponds to observations made in the intact cell using other, notably electrophysiological, measurements. The review also critically evaluates the limitations of the approach and thereby tries to set the work on isolated membranes in the proper perspective within the field of transport physiology.
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Issaurat B, Amblard G, Gavach C. Electrical manifestation of ion transport across black lipid membranes generated by a Na+/K+ ATPase. FEBS Lett 1980; 115:148-50. [PMID: 6248376 DOI: 10.1016/0014-5793(80)80746-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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326 - Electrical charge fluxes across bimolecular lipidic membranes associated with ATP hydrolysis catalyzed by a Na+/K+ ATPase. ACTA ACUST UNITED AC 1980. [DOI: 10.1016/0302-4598(80)87011-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Chapter 26 Relationship between Localization of Na+-K+-ATPase, Cellular Fine Structure, and Reabsorptive and Secretory Electrolyte Transport. ACTA ACUST UNITED AC 1980. [DOI: 10.1016/s0070-2161(08)60294-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
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Electrical charge fluxes across bimolecular lipidic membranes associated with ATP hydrolysis catalyzed by a Na+/K+ ATPase. ACTA ACUST UNITED AC 1980. [DOI: 10.1016/s0022-0728(80)80249-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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