Abstract
Adsorption of Na+/K+-ATPase containing membrane fragments from pig kidney to lipid membranes allows the detection of electrogenic events during the Na+/K+-ATPase reaction cycle with high sensitivity and time resolution. High stability preparations can be obtained using solid supported membranes (SSM) as carrier electrodes for the membrane fragments. The SSMs are prepared using an alkanethiol monolayer covalently linked to a gold surface on a glass substrate. The hydrophobic surface is covered with a lipid monolayer (SAM, self-assembled monolayer) to obtain a double layer system having electrical properties similar to those of unsupported bilayer membranes (BLM). As we have previously shown (, Biophys. J. 64:384-391), the Na+/K+-ATPase on a SSM can be activated by photolytic release of ATP from caged ATP. In this publication we show the first results of a new technique which allows rapid solution exchange at the membrane surface making use of the high mechanical stability of SSM preparations. Especially for substrates, which are not available as a caged substance-such as Na+ and K+-this technique is shown to be capable of yielding new results. The Na+/K+-ATPase was activated by rapid concentration jumps of ATP and Na+ (in the presence of ATP). A time resolution of up to 10 ms was obtained in these experiments. The aim of this paper is to present the new technique together with the first results obtained from the investigation of the Na+/K+-ATPase. A comparison with data taken from the literature shows considerable agreement with our experiments.
Full Text
The Full Text of this article is available as a PDF (179.5 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bamberg E., Butt H. J., Eisenrauch A., Fendler K. Charge transport of ion pumps on lipid bilayer membranes. Q Rev Biophys. 1993 Feb;26(1):1–25. doi: 10.1017/s0033583500003942. [DOI] [PubMed] [Google Scholar]
- Barry P. H., Diamond J. M. Effects of unstirred layers on membrane phenomena. Physiol Rev. 1984 Jul;64(3):763–872. doi: 10.1152/physrev.1984.64.3.763. [DOI] [PubMed] [Google Scholar]
- Borlinghaus R., Apell H. J., Läuger P. Fast charge translocations associated with partial reactions of the Na,K-pump: I. Current and voltage transients after photochemical release of ATP. J Membr Biol. 1987;97(3):161–178. doi: 10.1007/BF01869220. [DOI] [PubMed] [Google Scholar]
- Fendler K., Grell E., Bamberg E. Kinetics of pump currents generated by the Na+,K+-ATPase. FEBS Lett. 1987 Nov 16;224(1):83–88. doi: 10.1016/0014-5793(87)80427-1. [DOI] [PubMed] [Google Scholar]
- Fendler K., Grell E., Haubs M., Bamberg E. Pump currents generated by the purified Na+K+-ATPase from kidney on black lipid membranes. EMBO J. 1985 Dec 1;4(12):3079–3085. doi: 10.1002/j.1460-2075.1985.tb04048.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fendler K., Jaruschewski S., Hobbs A., Albers W., Froehlich J. P. Pre-steady-state charge translocation in NaK-ATPase from eel electric organ. J Gen Physiol. 1993 Oct;102(4):631–666. doi: 10.1085/jgp.102.4.631. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Franke C., Hatt H., Dudel J. Liquid filament switch for ultra-fast exchanges of solutions at excised patches of synaptic membrane of crayfish muscle. Neurosci Lett. 1987 Jun 15;77(2):199–204. doi: 10.1016/0304-3940(87)90586-6. [DOI] [PubMed] [Google Scholar]
- Friedrich T., Bamberg E., Nagel G. Na+,K(+)-ATPase pump currents in giant excised patches activated by an ATP concentration jump. Biophys J. 1996 Nov;71(5):2486–2500. doi: 10.1016/S0006-3495(96)79442-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Friedrich T., Nagel G. Comparison of Na+/K(+)-ATPase pump currents activated by ATP concentration or voltage jumps. Biophys J. 1997 Jul;73(1):186–194. doi: 10.1016/S0006-3495(97)78059-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gadsby D. C., Nakao M. Steady-state current-voltage relationship of the Na/K pump in guinea pig ventricular myocytes. J Gen Physiol. 1989 Sep;94(3):511–537. doi: 10.1085/jgp.94.3.511. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goldshlegger R., Karlish S. J., Rephaeli A., Stein W. D. The effect of membrane potential on the mammalian sodium-potassium pump reconstituted into phospholipid vesicles. J Physiol. 1987 Jun;387:331–355. doi: 10.1113/jphysiol.1987.sp016576. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Heyse S., Wuddel I., Apell H. J., Stürmer W. Partial reactions of the Na,K-ATPase: determination of rate constants. J Gen Physiol. 1994 Aug;104(2):197–240. doi: 10.1085/jgp.104.2.197. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jorgensen P. L. Purification and characterization of (Na+ plus K+ )-ATPase. 3. Purification from the outer medulla of mammalian kidney after selective removal of membrane components by sodium dodecylsulphate. Biochim Biophys Acta. 1974 Jul 12;356(1):36–52. doi: 10.1016/0005-2736(74)90292-2. [DOI] [PubMed] [Google Scholar]
- Kane D. J., Fendler K., Grell E., Bamberg E., Taniguchi K., Froehlich J. P., Clarke R. J. Stopped-flow kinetic investigations of conformational changes of pig kidney Na+,K+-ATPase. Biochemistry. 1997 Oct 28;36(43):13406–13420. doi: 10.1021/bi970598w. [DOI] [PubMed] [Google Scholar]
- Kaplan J. H., Forbush B., 3rd, Hoffman J. F. Rapid photolytic release of adenosine 5'-triphosphate from a protected analogue: utilization by the Na:K pump of human red blood cell ghosts. Biochemistry. 1978 May 16;17(10):1929–1935. doi: 10.1021/bi00603a020. [DOI] [PubMed] [Google Scholar]
- McCray J. A., Herbette L., Kihara T., Trentham D. R. A new approach to time-resolved studies of ATP-requiring biological systems; laser flash photolysis of caged ATP. Proc Natl Acad Sci U S A. 1980 Dec;77(12):7237–7241. doi: 10.1073/pnas.77.12.7237. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nagel G., Fendler K., Grell E., Bamberg E. Na+ currents generated by the purified (Na+ + K+)-ATPase on planar lipid membranes. Biochim Biophys Acta. 1987 Jul 23;901(2):239–249. doi: 10.1016/0005-2736(87)90120-9. [DOI] [PubMed] [Google Scholar]
- Pratap P. R., Robinson J. D., Steinberg M. I. The reaction sequence of the Na+/K(+)-ATPase: rapid kinetic measurements distinguish between alternative schemes. Biochim Biophys Acta. 1991 Nov 4;1069(2):288–298. doi: 10.1016/0005-2736(91)90137-w. [DOI] [PubMed] [Google Scholar]
- Seifert K., Fendler K., Bamberg E. Charge transport by ion translocating membrane proteins on solid supported membranes. Biophys J. 1993 Feb;64(2):384–391. doi: 10.1016/S0006-3495(93)81379-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Steinberg M., Karlish S. J. Studies on conformational changes in Na,K-ATPase labeled with 5-iodoacetamidofluorescein. J Biol Chem. 1989 Feb 15;264(5):2726–2734. [PubMed] [Google Scholar]