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. 1992 May;61(5):1353–1363. doi: 10.1016/S0006-3495(92)81942-2

Lipid surface charge does not influence conductance or calcium block of single sodium channels in planar bilayers.

J F Worley 3rd 1, R J French 1, B A Pailthorpe 1, B K Krueger 1
PMCID: PMC1260397  PMID: 1318097

Abstract

We have studied the effects of membrane surface charge on Na+ ion permeation and Ca2+ block in single, batrachotoxin-activated Na channels from rat brain, incorporated into planar lipid bilayers. In phospholipid membranes with no net charge (phosphatidylethanolamine, PE), at low divalent cation concentrations (approximately 100 microM Mg2+), the single channel current-voltage relation was linear and the single channel conductance saturated with increasing [Na+] and ionic strength, reaching a maximum (gamma max) of 31.8 pS, with an apparent dissociation constant (K0.5) of 40.5 mM. The data could be approximated by a rectangular hyperbola. In negatively charged bilayers (70% phosphatidylserine, PS; 30% PE) slightly larger conductances were observed at each concentration, but the hyperbolic form of the conductance-concentration relation was retained (gamma max = 32.9 pS and K0.5 = 31.5 mM) without any preferential increase in conductance at lower ionic strengths. Symmetrical application of Ca2+ caused a voltage-dependent block of the single channel current, with the block being greater at negative potentials. For any given voltage and [Na+] this block was identical in neutral and negatively charged membranes. These observations suggest that both the conduction pathway and the site(s) of Ca2+ block of the rat brain Na channel protein are electrostatically isolated from the negatively charged headgroups on the membrane lipids.

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Selected References

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  1. Behrens M. I., Oberhauser A., Bezanilla F., Latorre R. Batrachotoxin-modified sodium channels from squid optic nerve in planar bilayers. Ion conduction and gating properties. J Gen Physiol. 1989 Jan;93(1):23–41. doi: 10.1085/jgp.93.1.23. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bell J. E., Miller C. Effects of phospholipid surface charge on ion conduction in the K+ channel of sarcoplasmic reticulum. Biophys J. 1984 Jan;45(1):279–287. doi: 10.1016/S0006-3495(84)84154-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Cai M., Jordan P. C. How does vestibule surface charge affect ion conduction and toxin binding in a sodium channel? Biophys J. 1990 Apr;57(4):883–891. doi: 10.1016/S0006-3495(90)82608-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Cecchi X., Alvarez O., Latorre R. A three-barrier model for the hemocyanin channel. J Gen Physiol. 1981 Dec;78(6):657–681. doi: 10.1085/jgp.78.6.657. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Coronado R., Affolter H. Insulation of the conduction pathway of muscle transverse tubule calcium channels from the surface charge of bilayer phospholipid. J Gen Physiol. 1986 Jun;87(6):933–953. doi: 10.1085/jgp.87.6.933. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Correa A. M., Latorre R., Bezanilla F. Ion permeation in normal and batrachotoxin-modified Na+ channels in the squid giant axon. J Gen Physiol. 1991 Mar;97(3):605–625. doi: 10.1085/jgp.97.3.605. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Cukierman S., Zinkand W. C., French R. J., Krueger B. K. Effects of membrane surface charge and calcium on the gating of rat brain sodium channels in planar bilayers. J Gen Physiol. 1988 Oct;92(4):431–447. doi: 10.1085/jgp.92.4.431. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Eisenberg M., Gresalfi T., Riccio T., McLaughlin S. Adsorption of monovalent cations to bilayer membranes containing negative phospholipids. Biochemistry. 1979 Nov 13;18(23):5213–5223. doi: 10.1021/bi00590a028. [DOI] [PubMed] [Google Scholar]
  9. French R. J., Worley J. F., 3rd, Krueger B. K. Voltage-dependent block by saxitoxin of sodium channels incorporated into planar lipid bilayers. Biophys J. 1984 Jan;45(1):301–310. doi: 10.1016/S0006-3495(84)84156-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Green W. N., Weiss L. B., Andersen O. S. Batrachotoxin-modified sodium channels in planar lipid bilayers. Characterization of saxitoxin- and tetrodotoxin-induced channel closures. J Gen Physiol. 1987 Jun;89(6):873–903. doi: 10.1085/jgp.89.6.873. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Green W. N., Weiss L. B., Andersen O. S. Batrachotoxin-modified sodium channels in planar lipid bilayers. Ion permeation and block. J Gen Physiol. 1987 Jun;89(6):841–872. doi: 10.1085/jgp.89.6.841. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. HODGKIN A. L., HUXLEY A. F. Currents carried by sodium and potassium ions through the membrane of the giant axon of Loligo. J Physiol. 1952 Apr;116(4):449–472. doi: 10.1113/jphysiol.1952.sp004717. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Hartshorne R. P., Catterall W. A. The sodium channel from rat brain. Purification and subunit composition. J Biol Chem. 1984 Feb 10;259(3):1667–1675. [PubMed] [Google Scholar]
  14. Hille B. Ionic selectivity, saturation, and block in sodium channels. A four-barrier model. J Gen Physiol. 1975 Nov;66(5):535–560. doi: 10.1085/jgp.66.5.535. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Hille B. The permeability of the sodium channel to organic cations in myelinated nerve. J Gen Physiol. 1971 Dec;58(6):599–619. doi: 10.1085/jgp.58.6.599. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Krueger B. K., Ratzlaff R. W., Strichartz G. R., Blaustein M. P. Saxitoxin binding to synaptosomes, membranes, and solubilized binding sites from rat brain. J Membr Biol. 1979 Nov 30;50(3-4):287–310. doi: 10.1007/BF01868894. [DOI] [PubMed] [Google Scholar]
  17. Krueger B. K., Worley J. F., 3rd, French R. J. Single sodium channels from rat brain incorporated into planar lipid bilayer membranes. Nature. 1983 May 12;303(5913):172–175. doi: 10.1038/303172a0. [DOI] [PubMed] [Google Scholar]
  18. Levinson S. R., Thornhill W. B., Duch D. S., Recio-Pinto E., Urban B. W. The role of nonprotein domains in the function and synthesis of voltage-gated sodium channels. Ion Channels. 1990;2:33–64. doi: 10.1007/978-1-4615-7305-0_2. [DOI] [PubMed] [Google Scholar]
  19. Loosley-Millman M. E., Rand R. P., Parsegian V. A. Effects of monovalent ion binding and screening on measured electrostatic forces between charged phospholipid bilayers. Biophys J. 1982 Dec;40(3):221–232. doi: 10.1016/S0006-3495(82)84477-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. MacKinnon R., Latorre R., Miller C. Role of surface electrostatics in the operation of a high-conductance Ca2+-activated K+ channel. Biochemistry. 1989 Oct 3;28(20):8092–8099. doi: 10.1021/bi00446a020. [DOI] [PubMed] [Google Scholar]
  21. McCarthy M. P., Earnest J. P., Young E. F., Choe S., Stroud R. M. The molecular neurobiology of the acetylcholine receptor. Annu Rev Neurosci. 1986;9:383–413. doi: 10.1146/annurev.ne.09.030186.002123. [DOI] [PubMed] [Google Scholar]
  22. McLaughlin A., Eng W. K., Vaio G., Wilson T., McLaughlin S. Dimethonium, a divalent cation that exerts only a screening effect on the electrostatic potential adjacent to negatively charged phospholipid bilayer membranes. J Membr Biol. 1983;76(2):183–193. doi: 10.1007/BF02000618. [DOI] [PubMed] [Google Scholar]
  23. McLaughlin S. G., Szabo G., Eisenman G., Ciani S. M. Surface charge and the conductance of phospholipid membranes. Proc Natl Acad Sci U S A. 1970 Nov;67(3):1268–1275. doi: 10.1073/pnas.67.3.1268. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. McLaughlin S. G., Szabo G., Eisenman G. Divalent ions and the surface potential of charged phospholipid membranes. J Gen Physiol. 1971 Dec;58(6):667–687. doi: 10.1085/jgp.58.6.667. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. McLaughlin S., Mulrine N., Gresalfi T., Vaio G., McLaughlin A. Adsorption of divalent cations to bilayer membranes containing phosphatidylserine. J Gen Physiol. 1981 Apr;77(4):445–473. doi: 10.1085/jgp.77.4.445. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. McLaughlin S. The electrostatic properties of membranes. Annu Rev Biophys Biophys Chem. 1989;18:113–136. doi: 10.1146/annurev.bb.18.060189.000553. [DOI] [PubMed] [Google Scholar]
  27. Moczydlowski E., Alvarez O., Vergara C., Latorre R. Effect of phospholipid surface charge on the conductance and gating of a Ca2+-activated K+ channel in planar lipid bilayers. J Membr Biol. 1985;83(3):273–282. doi: 10.1007/BF01868701. [DOI] [PubMed] [Google Scholar]
  28. Moczydlowski E., Garber S. S., Miller C. Batrachotoxin-activated Na+ channels in planar lipid bilayers. Competition of tetrodotoxin block by Na+. J Gen Physiol. 1984 Nov;84(5):665–686. doi: 10.1085/jgp.84.5.665. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Mozhayeva G. N., Naumov A. P., Nosyreva E. D. Potential-dependent calcium blockage of normal and aconitine-modified sodium channels in frog node of Ranvier. Gen Physiol Biophys. 1985 Aug;4(4):425–427. [PubMed] [Google Scholar]
  30. Neumcke B., Stämpfli R. Heterogeneity of external surface charges near sodium channels in the nodal membrane of frog nerve. Pflugers Arch. 1984 Jun;401(2):125–131. doi: 10.1007/BF00583872. [DOI] [PubMed] [Google Scholar]
  31. Ravindran A., Kwiecinski H., Alvarez O., Eisenman G., Moczydlowski E. Modeling ion permeation through batrachotoxin-modified Na+ channels from rat skeletal muscle with a multi-ion pore. Biophys J. 1992 Feb;61(2):494–508. doi: 10.1016/S0006-3495(92)81854-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Sheets M. F., Scanley B. E., Hanck D. A., Makielski J. C., Fozzard H. A. Open sodium channel properties of single canine cardiac Purkinje cells. Biophys J. 1987 Jul;52(1):13–22. doi: 10.1016/S0006-3495(87)83183-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Woodhull A. M. Ionic blockage of sodium channels in nerve. J Gen Physiol. 1973 Jun;61(6):687–708. doi: 10.1085/jgp.61.6.687. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Worley J. F., 3rd, French R. J., Krueger B. K. Trimethyloxonium modification of single batrachotoxin-activated sodium channels in planar bilayers. Changes in unit conductance and in block by saxitoxin and calcium. J Gen Physiol. 1986 Feb;87(2):327–349. doi: 10.1085/jgp.87.2.327. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Yamamoto D., Yeh J. Z., Narahashi T. Interactions of permeant cations with sodium channels of squid axon membranes. Biophys J. 1985 Sep;48(3):361–368. doi: 10.1016/S0006-3495(85)83792-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Yamamoto D., Yeh J. Z., Narahashi T. Voltage-dependent calcium block of normal and tetramethrin-modified single sodium channels. Biophys J. 1984 Jan;45(1):337–344. doi: 10.1016/S0006-3495(84)84159-4. [DOI] [PMC free article] [PubMed] [Google Scholar]

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