Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Subconductance states of single sodium channels modified by chloramine-T and sea anemone toxin in neuroblastoma cells

  • 35 Accesses

  • 29 Citations


Single channel currents of chloramine-T (Chl-T) and sea anemone toxin (ATX-II) modified sodium channels were studied in neuroblastoma cells. With both substances similar subconductance states have been observed. The conductances of the sublevels were multiples of the “unit” step which was about onefourth of the most frequently occurring main conductance. Thus, the current levels observed were one fourth, half and five-fourths of the main current size. Both substances caused a slower decay of the averaged current compared to the current of the native channels. The main single-channel conductance was 15.2 pS (T=16°C) for the Chl-T and 10.8 pS (T=12°C) for the ATX-II modified channels. The channel open time was doubled by ATX-II, but was not increased significantly by Chl-T. The existence of the subconductance states suggests that the native channels may also have multiple open conformations.

This is a preview of subscription content, log in to check access.


  1. Auerbach A, Sachs F (1983) Flickering of a nicotinic ion channel to a subconductance state. Biophys J 42:1–10

  2. Barrett JN, Magleby KL, Pallotta BS (1982) Properties of single calcium-activated potassium channels in cultured rat muscle. J Physiol (London) 331:211–230

  3. Carbone E, Lux HD (1986) Na channels in cultured chick dorsal root ganglion neurons. Eur Biophys J 13:259–271

  4. Chinn K, Narahashi T (1986) Stabilization of sodium channel states by deltamethrin in mause neuroblastoma cells. J Physiol (London) 380:191–207

  5. Colquhoun D, Sakmann B (1985) Fast events in single-channel currents activated by acetylcholine and its analogues at the frog muscle end-plate. J Physiol (London) 369:501–557

  6. Colquhoun D, Sigworth FJ (1983) Fitting and statistical analysis of single-channel records. In: Sakmann B, Neher E (ed) Single-channel recording. Plenum Press, New York, pp 191–263

  7. Hamill OP, Sakmann B (1981) Multiple conductance states of single acetylcholine receptor channels in embryonic cells. Nature 194:462–464

  8. Hamill OP, Marty A, Neher E, Sakmann B, Sigworth FJ (1981) Improved patch clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflügers Arch Eur J Physiol 391:85–100

  9. Hof D (1986) A pulse generating and data recording system based on the microcomputer PDP 11/23. Comput Method Program Biomed 23:309–315

  10. Labarca PP, Miller C (1981) A K+-selective, three-state channel from fragmented sarcoplasmic reticulum of frog leg muscle. J Membr Biol 61:31–38

  11. Nagy K, Kiss T, Hof D (1983) Single Na channels in mouse neuroblastoma cell membrane. Indications for two open states. Pflügers Arch Eur J Physiol 399:302–308

  12. Patlak J, Horn R (1982) Effect of N-bromoacetamide on single sodium channel currents in excised membrane patches. J Gen Physiol 79:333–351

  13. Sachs F (1983) Is the acetylcholine receptor a unit-conductance channel? In: Sakmann B, Neher E (eds) Single-channel recording. Plenum Press, New York, pp 365–376

  14. Sakmann B, Trube G (1984) Conductance properties of single inwardly rectifying potassium channels in ventricular cells from guinea-pig heart. J Physiol 347:641–657

  15. Schreibmeyer W, Kazerani H, Tritthart HA (1986) Analyses of the mode of action of ATX-II on single sodium channels from isolated rat ventricular cells. Naunyn-Schmiedeberg's Arch Pharmacol 334:R11

  16. Wang GK (1984) Irreversible modification of sodium channel inactivation in toad myelinated nerve fibres by the oxidant chloramine-T. J Physiol (London) 346:127–141

  17. Wang GK, Brodwick MS, Eaton DC (1985) Removal of sodium channel inactivation in squid axon by the oxidant chloramine-T. J Gen Physiol 86:289–302

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Nagy, K. Subconductance states of single sodium channels modified by chloramine-T and sea anemone toxin in neuroblastoma cells. Eur Biophys J 15, 129–132 (1987).

Download citation

Key words

  • Single sodium channels
  • multiple conductance states
  • chloramine-T
  • sea anemone toxin
  • neuroblastoma