Summary
The electrogenic properties of the Na,K-ATPase can be studied by correlating transient electrical events in the pump molecule with optically-detected conformational changes. Membrane fragments containing a high density of oriented ATPase molecules can be bound to a planar bilayer acting as a capacitive electrode. Flash-induced ATP-release in the solution from “caged” ATP elicits transient electrical signals in the external measuring circuit, reflecting charge movements in the pump molecule. In parallel experiments, optical signals resulting from conformational transitions were recorded from fluorescence-labeled Na,K-ATPase. From the comparison of electrical and optical transients recorded under a variety of conditions, information on the nature of the charge-translocating steps in the pumping cycle can be obtained.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Apell, H.-J., Borlinghaus, R., and Läuger, P. (1987). Fast charge-translocations associated with partial reactions of the Na,K-pump. II. Microscopic analysis of transient currents. J. Membrane Biol. 97: 179–191
Apell, H.-J., Borlinghaus, R., and Läuger, P. (1987). Fast charge-translocations associated with partial reactions of the Na,K-pump. II. Microscopic analysis of transient currents. J. Membrane Biol. 97: 179–191
Bahinski, A., Nakao, M., and Gadsby, D.C. (1988). Potassium translocation by the Na/K pump is voltage insensitive. Proc. Natl. Acad. Sci. USA 85: 34123416
Borlinghaus, R., Apell, H.-J., and Läuger, P. (1987). Fast charge-translocations associated with partial reactions of the Na,K-pump. I. Current and voltage transients after photochemical release of ATP. J. Membrane Biol. 97: 161–178
Cantley, L.C., Carili, C.T., Smith, R.L., and Perlman, D. (1984). Conformational changes of Na,K-ATPase necessary for transport. Curr. Top. Membr. Transp. 19: 315–322
Deguchi, N., Jorgensen, P.L., and Maunsbach, A.B. (1977). Ultrastructure of the sodium pump. Comparison of thin sectioning, negative staining, and freeze-fracture of purified, membrane-bound (Na+,e)-ATPase. J. Cell Biol. 75: 619–634
Fendler, K., Grell, E., Haubs M., and Bamberg, E. (1985). Pump currents generated by the purified Na?,K+-ATPase from kidney on black lipid membranes. EMBO J. 4: 3079–3085
Glynn, I.M., and Karlish, S.J.D. (1976). ATP hydrolysis associated with an uncoupled sodium flux through the sodium pump: Evidence for allosteric effects of intracellular ATP and extracellular sodium. J. Physiol. (London) 256: 465–496
Glynn, I.M. (1985). In: The Enzymes of Biological Membranes, 2nd ed., Vol. 3, (A.N. Martonosi, ed.), Plenum, New York, pp. 35–114
Goldshlegger, R., Karlish, S.J.D., Rephaeli, A., and Stein, W.D. (1987). The effect of membrane potential on the mammalian sodium-potassium pump reconstituted into phospholipid vesicles. J. Physiol. (London) 387: 331–355
Jorgensen, P.L., and Andersen, J.P. (1988). Structural basis for E1–E2 conformational transitions in Na,K-pump and Ca-pump proteins. J. Membrane Biol. 103: 95–120
Kapakos, J.G., and Steinberg, M. (1986). 5-Iodoacetamidofluorescein-labeled (Na,K)-ATPase. Steady-state fluorescence during turnover. J. Biol. Chem. 261: 2090–2096
Karlish, S.J.D., Yates, D.W., and Glynn, I.M. (1978). Elementary steps of the (Na++K+)-ATPase mechanism, studied with formycin nucleotides. Biochim. Biophys. Acta 525: 230–251
Karlish, S.J.D. (1980). Characterization of conformational changes in (Na,K)ATPase labeled with fluorescein at the active site. J. Bioenerg. Biomembr. 12: 111–135
Läuger, P., and Apell, H.-J. (1988). Transient behaviour of the Na+/K+-pump: microscopic analysis of nonstationary ion-translocation. Biochim. Biophys. Acta 944: 451–464
McCray, J.A., Herbette, L., Kihara, T., and Trentham, D.R. (1980). A new approach to time-resolved studies of ATP-requiring biological systems: Laserflash photolysis of caged ATP. Proc. Natl. Acad. Sci. USA 77: 72377241
Nakao, M., and Gadsby, D.C. (1986). Voltage dependence of Na translocation by the Na/K pump. Nature (London) 323: 628–630
Steinberg, M., and Karlish, S.J.D. (1989). Studies on conformational changes in Na,K-ATPase labeled with 5-iodoacetamidofluorescein. J. Biol. Chem. 264: 2726–2734
Steinberg, M., and Karlish, S.J.D. (1989). Studies on conformational changes in Na,K-ATPase labeled with 5-iodoacetamidofluorescein. J. Biol. Chem. 264: 2726–2734
Stürmer, W., Apell, H.-J., Wuddel, I., and Läuger, P. (1989). Conformational transitions and charge translocation by the Na,K pump: comparison of optical and electrical transients elicited by ATP-concentration jumps. J. Membr. Biol. (in press)
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1990 Birkhäuser Verlag Basel
About this chapter
Cite this chapter
Apell, HJ., Borlinghaus, R., Läuger, P., Stürmer, W., Wuddel, I. (1990). Ion Translocation by the Na,K-Pump: Correlation between Electrogenic Events and Conformational Transitions. In: Vasilescu, D., Jaz, J., Packer, L., Pullman, B. (eds) Water and Ions in Biomolecular Systems. Advances in Life Sciences. Birkhäuser Basel. https://doi.org/10.1007/978-3-0348-7253-9_18
Download citation
DOI: https://doi.org/10.1007/978-3-0348-7253-9_18
Publisher Name: Birkhäuser Basel
Print ISBN: 978-3-0348-7255-3
Online ISBN: 978-3-0348-7253-9
eBook Packages: Springer Book Archive