Skip to main content
NCBI home page
The Journal of General Physiology logoLink to The Journal of General Physiology
. 1986 Jun 1;87(6):933–953. doi: 10.1085/jgp.87.6.933

Insulation of the conduction pathway of muscle transverse tubule calcium channels from the surface charge of bilayer phospholipid

PMCID: PMC2215864  PMID: 2425043

Abstract

Functional calcium channels present in purified skeletal muscle transverse tubules were inserted into planar phospholipid bilayers composed of the neutral lipid phosphatidylethanolamine (PE), the negatively charged lipid phosphatidylserine (PS), and mixtures of both. The lengthening of the mean open time and stabilization of single channel fluctuations under constant holding potentials was accomplished by the use of the agonist Bay K8644. It was found that the barium current carried through the channel saturates as a function of the BaCl2 concentration at a maximum current of 0.6 pA (at a holding potential of 0 mV) and a half-saturation value of 40 mM. Under saturation, the slope conductance of the channel is 20 pS at voltages more negative than -50 mV and 13 pS at a holding potential of 0 mV. At barium concentrations above and below the half-saturation point, the open channel currents were independent of the bilayer mole fraction of PS from XPS = 0 (pure PE) to XPS = 1.0 (pure PS). It is shown that in the absence of barium, the calcium channel transports sodium or potassium ions (P Na/PK = 1.4) at saturating rates higher than those for barium alone. The sodium conductance in pure PE bilayers saturates as a function of NaCl concentration, following a curve that can be described as a rectangular hyperbola with a half-saturation value of 200 mM and a maximum conductance of 68 pS (slope conductance at a holding potential of 0 mV). In pure PS bilayers, the sodium conductance is about twice that measured in PE at concentrations below 100 mM NaCl. The maximum channel conductance at high ionic strength is unaffected by the lipid charge. This effect at low ionic strength was analyzed according to J. Bell and C. Miller (1984. Biophysical Journal. 45:279- 287) and interpreted as if the conduction pathway of the calcium channel were separated from the bilayer lipid by approximately 20 A. This distance thereby effectively insulates the ion entry to the channel from the bulk of the bilayer lipid surface charge. Current vs. voltage curves measured in NaCl in pure PE and pure PS show that similarly small surface charge effects are present in both inward and outward currents. This suggests that the same conduction insulation is present at both ends of the calcium channel.

Full Text

The Full Text of this article is available as a PDF (1.2 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Affolter H., Coronado R. Agonists Bay-K8644 and CGP-28392 open calcium channels reconstituted from skeletal muscle transverse tubules. Biophys J. 1985 Aug;48(2):341–347. doi: 10.1016/S0006-3495(85)83789-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Affolter H., Coronado R. Sidedness of reconstituted calcium channels from muscle transverse tubules as determined by D600 and D890 blockade. Biophys J. 1986 Mar;49(3):767–771. doi: 10.1016/S0006-3495(86)83703-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Akaike N., Lee K. S., Brown A. M. The calcium current of Helix neuron. J Gen Physiol. 1978 May;71(5):509–531. doi: 10.1085/jgp.71.5.509. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Almers W., McCleskey E. W. Non-selective conductance in calcium channels of frog muscle: calcium selectivity in a single-file pore. J Physiol. 1984 Aug;353:585–608. doi: 10.1113/jphysiol.1984.sp015352. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Apell H. J., Bamberg E., Läuger P. Effects of surface charge on the conductance of the gramicidin channel. Biochim Biophys Acta. 1979 Apr 19;552(3):369–378. doi: 10.1016/0005-2736(79)90181-0. [DOI] [PubMed] [Google Scholar]
  6. Begenisich T. Magnitude and location of surface charges on Myxicola giant axons. J Gen Physiol. 1975 Jul;66(1):47–65. doi: 10.1085/jgp.66.1.47. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. 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]
  8. Borsotto M., Norman R. I., Fosset M., Lazdunski M. Solubilization of the nitrendipine receptor from skeletal muscle transverse tubule membranes. Interactions with specific inhibitors of the voltage-dependent Ca2+ channel. Eur J Biochem. 1984 Aug 1;142(3):449–455. doi: 10.1111/j.1432-1033.1984.tb08307.x. [DOI] [PubMed] [Google Scholar]
  9. Butler J. N. The thermodynamic activity of calcium ion in sodium chloride-calcium chloride electrolytes. Biophys J. 1968 Dec;8(12):1426–1433. doi: 10.1016/S0006-3495(68)86564-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Byerly L., Chase P. B., Stimers J. R. Permeation and interaction of divalent cations in calcium channels of snail neurons. J Gen Physiol. 1985 Apr;85(4):491–518. doi: 10.1085/jgp.85.4.491. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Carnie S., McLaughlin S. Large divalent cations and electrostatic potentials adjacent to membranes. A theoretical calculation. Biophys J. 1983 Dec;44(3):325–332. doi: 10.1016/S0006-3495(83)84306-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Coronado R., Rosenberg R. L., Miller C. Ionic selectivity, saturation, and block in a K+-selective channel from sarcoplasmic reticulum. J Gen Physiol. 1980 Oct;76(4):425–446. doi: 10.1085/jgp.76.4.425. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Cota G., Stefani E. Saturation of calcium channels and surface charge effects in skeletal muscle fibres of the frog. J Physiol. 1984 Jun;351:135–154. doi: 10.1113/jphysiol.1984.sp015238. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Criado M., Eibl H., Barrantes F. J. Functional properties of the acetylcholine receptor incorporated in model lipid membranes. Differential effects of chain length and head group of phospholipids on receptor affinity states and receptor-mediated ion translocation. J Biol Chem. 1984 Jul 25;259(14):9188–9198. [PubMed] [Google Scholar]
  15. Curtis B. M., Catterall W. A. Purification of the calcium antagonist receptor of the voltage-sensitive calcium channel from skeletal muscle transverse tubules. Biochemistry. 1984 May 8;23(10):2113–2118. doi: 10.1021/bi00305a001. [DOI] [PubMed] [Google Scholar]
  16. FRANKENHAEUSER B., HODGKIN A. L. The action of calcium on the electrical properties of squid axons. J Physiol. 1957 Jul 11;137(2):218–244. doi: 10.1113/jphysiol.1957.sp005808. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Ferry D. R., Goll A., Glossmann H. Differential labelling of putative skeletal muscle calcium channels by [3H]-nifedipine, [3H]-nitrendipine, [3H]-nimodipine and [3H]-PN 200 110. Naunyn Schmiedebergs Arch Pharmacol. 1983 Jul;323(3):276–277. doi: 10.1007/BF00497674. [DOI] [PubMed] [Google Scholar]
  18. Gilbert D. L., Ehrenstein G. Effect of divalent cations on potassium conductance of squid axons: determination of surface charge. Biophys J. 1969 Mar;9(3):447–463. doi: 10.1016/S0006-3495(69)86396-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Hagiwara S. Ca-dependent action potential. Membranes. 1975;3:359–381. [PubMed] [Google Scholar]
  20. Hahin R., Campbell D. T. Simple shifts in the voltage dependence of sodium channel gating caused by divalent cations. J Gen Physiol. 1983 Dec;82(6):785–805. doi: 10.1085/jgp.82.6.785. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Hess P., Tsien R. W. Mechanism of ion permeation through calcium channels. 1984 May 31-Jun 6Nature. 309(5967):453–456. doi: 10.1038/309453a0. [DOI] [PubMed] [Google Scholar]
  22. Hille B., Woodhull A. M., Shapiro B. I. Negative surface charge near sodium channels of nerve: divalent ions, monovalent ions, and pH. Philos Trans R Soc Lond B Biol Sci. 1975 Jun 10;270(908):301–318. doi: 10.1098/rstb.1975.0011. [DOI] [PubMed] [Google Scholar]
  23. Kistler J., Stroud R. M., Klymkowsky M. W., Lalancette R. A., Fairclough R. H. Structure and function of an acetylcholine receptor. Biophys J. 1982 Jan;37(1):371–383. doi: 10.1016/S0006-3495(82)84685-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Kostyuk P. G., Krishtal O. A., Doroshenko P. A. Calcium currents in snail neurones. II. The effect of external calcium concentration on the calcium inward current. Pflugers Arch. 1974 Apr 11;348(2):95–104. doi: 10.1007/BF00586472. [DOI] [PubMed] [Google Scholar]
  25. Lawson D. H., Miller A. W. Screening for bacteriuria in pregnancy. Lancet. 1971 Jan 2;1(7688):9–10. doi: 10.1016/s0140-6736(71)80003-x. [DOI] [PubMed] [Google Scholar]
  26. 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]
  27. McCleskey E. W., Almers W. The Ca channel in skeletal muscle is a large pore. Proc Natl Acad Sci U S A. 1985 Oct;82(20):7149–7153. doi: 10.1073/pnas.82.20.7149. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. 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]
  29. 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]
  30. 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]
  31. Mozhayeva G. N., Naumov A. P. Effect of surface charge on the steady-state potassium conductance of nodal membrane. Nature. 1970 Oct 10;228(5267):164–165. doi: 10.1038/228164a0. [DOI] [PubMed] [Google Scholar]
  32. Ohmori H., Yoshii M. Surface potential reflected in both gating and permeation mechanisms of sodium and calcium channels of the tunicate egg cell membrane. J Physiol. 1977 May;267(2):429–463. doi: 10.1113/jphysiol.1977.sp011821. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Rosemblatt M., Hidalgo C., Vergara C., Ikemoto N. Immunological and biochemical properties of transverse tubule membranes isolated from rabbit skeletal muscle. J Biol Chem. 1981 Aug 10;256(15):8140–8148. [PubMed] [Google Scholar]
  34. Weigele J. B., Barchi R. L. Functional reconstitution of the purified sodium channel protein from rat sarcolemma. Proc Natl Acad Sci U S A. 1982 Jun;79(11):3651–3655. doi: 10.1073/pnas.79.11.3651. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Wilson D. L., Morimoto K., Tsuda Y., Brown A. M. Interaction between calcium ions and surface charge as it relates to calcium currents. J Membr Biol. 1983;72(1-2):117–130. doi: 10.1007/BF01870319. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of General Physiology are provided here courtesy of The Rockefeller University Press

RESOURCES