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The modulatory site for the action of gadolinium on surface charges and channel gating.
Elinder F, Arhem P.
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The gadolinium (Gd3+)-induced shift of potential dependence and modulated gating of Na and K channels were analyzed. In a previous investigation, we explained the shift in terms of pure screening (no binding) of fixed surface charges and the modulation by binding to modulatory sites on the channels. In the present paper, we have extended this model by including effects on the charge density of Gd3+ binding to the modulatory sites. From fitting the extended model to experimental data, the charge density was estimated to be -0.6 e nm-2, and the Gd(3+)-induced charge change to be +0.15 e nm-2, and the maximal scaling factor to be 7.5 for both Na and K channels. Intrinsic KD values for binding to the K and Na channels were estimated to be 140 and 380 mM, respectively. Estimations of the extracellular charge density, from primary structures of cloned channels, were found to be in agreement with estimations based on the present model. The modulatory site was suggested to be located at the cluster of negatively charged residues between the fifth transmembrane segment (S5) and the pore-forming region for both Na and K channels. These suggestions imply several testable predictions about different K channels.
Arhem,
Effects of some heavy metal ions on the ionic currents of myelinated fibres from Xenopus laevis.
1980, Pubmed,
Xenbase
Arhem,
Effects of some heavy metal ions on the ionic currents of myelinated fibres from Xenopus laevis.
1980,
Pubmed
,
Xenbase Armstrong,
Modification of sodium channel gating by lanthanum. Some effects that cannot be explained by surface charge theory.
1990,
Pubmed Attwell,
Discrete membrane surface charge distributions. Effect of fluctuations near individual channels.
1978,
Pubmed Baldwin,
Characterization of a mammalian cDNA for an inactivating voltage-sensitive K+ channel.
1991,
Pubmed
,
Xenbase Beckh,
Members of the RCK potassium channel family are differentially expressed in the rat nervous system.
1990,
Pubmed Bell,
Effects of phospholipid surface charge on ion conduction in the K+ channel of sarcoplasmic reticulum.
1984,
Pubmed Chandy,
Simplified gene nomenclature.
1991,
Pubmed Cukierman,
Effects of membrane surface charge and calcium on the gating of rat brain sodium channels in planar bilayers.
1988,
Pubmed Dubois,
Evidence for the existence of three types of potassium channels in the frog Ranvier node membrane.
1981,
Pubmed Durell,
Atomic scale structure and functional models of voltage-gated potassium channels.
1992,
Pubmed Elinder,
Effects of gadolinium on ion channels in the myelinated axon of Xenopus laevis: four sites of action.
1994,
Pubmed
,
Xenbase Frankenhaeuser,
The effects of neuraminidase and protamine chloride on potential clamp parameters of the node of Ranvier (Xenopus laevis).
1976,
Pubmed
,
Xenbase Frech,
A novel potassium channel with delayed rectifier properties isolated from rat brain by expression cloning.
1989,
Pubmed
,
Xenbase GRAHAME,
The electrical double layer and the theory of electrocapillarity.
1947,
Pubmed Green,
Batrachotoxin-modified sodium channels in planar lipid bilayers. Ion permeation and block.
1987,
Pubmed Grupe,
Cloning and expression of a human voltage-gated potassium channel. A novel member of the RCK potassium channel family.
1990,
Pubmed
,
Xenbase Guy,
Pursuing the structure and function of voltage-gated channels.
1990,
Pubmed
,
Xenbase Hille,
Negative surface charge near sodium channels of nerve: divalent ions, monovalent ions, and pH.
1975,
Pubmed Hwang,
A novel K+ channel with unique localizations in mammalian brain: molecular cloning and characterization.
1992,
Pubmed Kayano,
Primary structure of rat brain sodium channel III deduced from the cDNA sequence.
1988,
Pubmed McLaughlin,
The electrostatic properties of membranes.
1989,
Pubmed Miller,
Hunting for the pore of voltage-gated channels.
1992,
Pubmed Noda,
Existence of distinct sodium channel messenger RNAs in rat brain.
,
Pubmed Numann,
Functional modulation of brain sodium channels by protein kinase C phosphorylation.
1991,
Pubmed Ohmori,
Surface potential reflected in both gating and permeation mechanisms of sodium and calcium channels of the tunicate egg cell membrane.
1977,
Pubmed Papazian,
Alteration of voltage-dependence of Shaker potassium channel by mutations in the S4 sequence.
1991,
Pubmed
,
Xenbase Pongs,
Molecular biology of voltage-dependent potassium channels.
1992,
Pubmed Pusch,
Divalent cations as probes for structure-function relationships of cloned voltage-dependent sodium channels.
1990,
Pubmed
,
Xenbase Recio-Pinto,
Neuraminidase treatment modifies the function of electroplax sodium channels in planar lipid bilayers.
1990,
Pubmed Rettig,
Characterization of a Shaw-related potassium channel family in rat brain.
1992,
Pubmed
,
Xenbase Safronov,
Single voltage-dependent potassium channels in rat peripheral nerve membrane.
1993,
Pubmed Sammar,
Depolarization exposes the voltage sensor of the sodium channels to the extracellular region.
1992,
Pubmed Spires,
Modification of potassium channel kinetics by amino group reagents.
1992,
Pubmed Spires,
Chemical properties of the divalent cation binding site on potassium channels.
1992,
Pubmed Stevens,
Ion channels. Making a submicroscopic hole in one.
1991,
Pubmed Stühmer,
Molecular basis of functional diversity of voltage-gated potassium channels in mammalian brain.
1989,
Pubmed
,
Xenbase Terlau,
Mapping the site of block by tetrodotoxin and saxitoxin of sodium channel II.
1991,
Pubmed
,
Xenbase Trimmer,
Primary structure and functional expression of a mammalian skeletal muscle sodium channel.
1989,
Pubmed
,
Xenbase Westenbroek,
Differential subcellular localization of the RI and RII Na+ channel subtypes in central neurons.
1989,
Pubmed Worley,
Lipid surface charge does not influence conductance or calcium block of single sodium channels in planar bilayers.
1992,
Pubmed
