Part of the Series of the Centro de Estudios Científicos de Santiago book series (SCEC)
The Use of Specific Ligands to Study Sodium Channels in Muscle
In the last 15 years the study of the ion channels as receptors for toxins, drugs, and hormones has yielded most of the information we now have on the biochemistry of these particular membrane protein molecules. Chemically gated channels are natural receptors and have been studied as such in several ways (see Barrantes, Chapter 24). In order to use this approach with voltage-gated channels, we need to have ligands that will bind to the channel with a fairly high specificity. Fortunately, nature has developed such molecules, at least for some voltage-gated channels, and binding of the ligand to the channel can be expressed according to the following reaction scheme:
where Ch is the channel molecule, L is the ligand, Ch-L represents the channel-ligand complex, and k 1 and k -1 are the rate constants for the association and dissociation reactions of the ligand with the channel, respectively.
$$Ch + LCh - L $$
KeywordsSodium Channel Sodium Current Muscle Membrane Mammalian Skeletal Muscle Frog Skeletal Muscle
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
Unable to display preview. Download preview PDF.
- Cahalan, M. D., 1975, Modification of sodium channel gating in frog myelenated nerve fibres by Centruroides sculpturatus scorpion venom, J. Physiol. (Lond.) 244:511–534.Google Scholar
- Caillé, J., Ildefonse, M., Rougier, O., and Roy, G., 1981, Surface and tubular membrane sodium currents in frog twitch muscle fibre; implication in excitation contraction coupling, Adv. Physiol. Sci. 5:389–409.Google Scholar
- Chen, C. J., Bean, B. P., Colatsky, T. J., and Tsien, R. W., 1981, Concentration dependenceGoogle Scholar
- of tetrodotoxin action on sodium currents and maximum upstroke velocity in rabbit cardiac Purkinje fibers, J. Gen. Physiol. 78:383–411.Google Scholar
- Fleckenstein, A., 1983, History of calcium antagonists, Circ. Res. 52:3–16.Google Scholar
- Frelin, C., Vigne, P., and Lazdunski, M., 1983, Na+ channels with high and low affinity tetrodotoxin binding sites in the mammalian skeletal muscle cell, J. Biol. Chem. 258:7256–7259.Google Scholar
- Hille, B., 1984, Ionic Channels of Excitable Membranes, Sinauer Associates, Sunderland, MA.Google Scholar
- Jaimovich, E., Ildefonse, M., Barhanin, J., Rougier, O., and Lazdunski, M., 1982, Centru-roides toxin, a selective blocker of surface Na+ channels in skeletal muscle: Voltage clamp analysis and biochemical characterization of the receptor, Proc. Natl. Acad. Sci. U.S.A. 79:3896–3900.PubMedCrossRefGoogle Scholar
- Jaimovich, E., Liberona, J. L., and Hidalgo, C., 1985, Characterization of two types of tetrodotoxin receptors in isolated frog muscle membranes, Biophys. J. 47:192a.Google Scholar
- Pappone, P. A., 1980, Voltage clamp experiments in normal and denervated mammalian skeletal muscle fibers, J. Physiol. (Lond.) 306:377–410.Google Scholar
© Plenum Press, New York 1986