Localization of voltage-sensitive sodium channels on the extrasynaptic membrane surface of mouse skeletal muscle by autoradiography of scorpion toxin binding sites

1990 ◽  
Vol 19 (3) ◽  
pp. 408-420 ◽  
Author(s):  
T. Le Treut ◽  
J. -L. Boudier ◽  
E. Jover ◽  
P. Cau
Keyword(s):  
Skeletal Muscle ◽  
Sodium Channels ◽  
Binding Sites ◽  
Membrane Surface ◽  
Scorpion Toxin ◽  
Mouse Skeletal Muscle ◽  
Toxin Binding ◽  
Extrasynaptic Membrane

scholarly journals The correlation between Na+ channel subunits and scorpion toxin-binding sites. A study in rat brain synaptosomes and in brain neurons developing in vitro.

1988 ◽  
Vol 263 (3) ◽  
pp. 1542-1548
Author(s):  
E Jover ◽  
A Massacrier ◽  
P Cau ◽  
M F Martin ◽  
F Couraud
Keyword(s):  
Rat Brain ◽  
Binding Sites ◽  
Scorpion Toxin ◽  
Na Channel ◽  
Brain Neurons ◽  
Rat Brain Synaptosomes ◽  
Toxin Binding ◽  
Brain Synaptosomes

scholarly journals Interaction of di-iodinated 125I-labelled α-bungarotoxin and reversible cholinergic ligands with intact synaptic acetylcholine receptors on isolated skeletal-muscle fibres from the rat

1979 ◽  
Vol 181 (3) ◽  
pp. 545-557 ◽  
Author(s):  
P Darveniza ◽  
J A Morgan-Hughes ◽  
E J Thompson
Keyword(s):  
Skeletal Muscle ◽  
Dissociation Constant ◽  
Binding Sites ◽  
Acetylcholine Receptors ◽  
Time Course ◽  
Muscle Fibres ◽  
First Order ◽  
Toxin Binding ◽  
Alpha Bungarotoxin ◽  
Skeletal Muscle Fibres

1. Intact synaptic acetylcholine receptors on freshly isolated rat skeletal-muscle fibres were characterized by their interaction with di-iodinated 125I-labelled alpha-bungarotoxin, acetylcholine and other cholinergic ligands at room temperature (22 deggrees C). 2. The time course and concentration dependence of 125I-labelled alpha-bungarotoxin association conformed to a bimolecular mechanism. In time-course experiments with different concentrations of 125I-labelled alpha-bungarotoxin (1.4–200 nM) the bimolecular-association rate constant, k + 1, was (2.27 +/- 0.49) × 10(4)M-1.S-1 (mean +/- S.D., N = 10). In concentration-dependence experiments, k + 1 was 2.10 × 10(4)M-1.S-1 and 1.74 × 10(4) M-1.S-1 with 10 and 135 min incubations respectively. In association experiments the first-order rate constant was proportional to the 125I-labelled alpha-bungarotoxin concentration. 125I-Labelled alpha-bungarotoxin dissociation was first order with a dissociation constant, k-1, less than or equal to 3 × 10(-6)S(-1) (half-life greater than or equal to 60 h.) The results indicated a single class of high-affinity toxin-binding sites at the end-plate with an equilibrium dissociation constant, Kd, equal to or less than 100 pM. The number of toxin-binding sites was (3.62 +/- 0.46) × 10(7) (mean +/- S.D., n = 22) per rat end-plate. 3. The apparent inhibitor dissociation constants, Ki, for reversible cholinergic ligands were determined by studying their effect at equilibrium on the rate of 125I-labelled alpha-bungarotoxin binding. There was heterogeneity of binding sites for cholinergic ligands, which were independent and non-interacting with antagonists. In contrast agonist affinity decreased with increasing receptor occupancy. Cholinergic ligands in excess inhibited over 90% of 125I-labelled alpha-bungarotoxin binding. 4. Cholinergic ligand binding was accompanied by an increase in entropy, which was greater for the agonist carbachol (delta So = +0.46 kJ.mol-1.K-1) than the antagonist tubocurarine (delta So = +0.26 kJ.mol-1.K-1). 5. The entropy and affinity changes that accompanied agonist binding suggested that agonists induced significant conformational changes in intact acetylcholine receptors. 6. The affinity and specificity of 125I-labelled alpha-bungarotoxin and tubocurarine binding to synaptic acetylcholine receptors from slow and fast muscle fibres were the same. 7. The study of binding only requires milligram amounts of tissue and may have application to other neurobiological studies and to the study of human neuromuscular disorders.

Ultrastructural visualization of Na+-channel associated[125]α-scorpion toxin binding sites on fetal mouse nerve cells in culture

1985 ◽  
Vol 20 (1) ◽  
pp. 137-142 ◽  
Author(s):  
J.A. Boudier ◽  
Y. Berwald-Netter ◽  
H.D. Dellmann ◽  
J.L. Boudier ◽  
F. Couraud ◽  
...  
Keyword(s):  
Binding Sites ◽  
Nerve Cells ◽  
Scorpion Toxin ◽  
Na Channel ◽  
Fetal Mouse ◽  
Toxin Binding ◽  
Cells In Culture

scholarly journals A new class of scorpion toxin binding sites related to an A-type K+ channel: pharmacological characterization and localization in rat brain

FEBS Letters ◽  
2001 ◽  
Vol 501 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Hélène Vacher ◽  
Régine Romi-Lebrun ◽  
Christiane Mourre ◽  
Bruno Lebrun ◽  
Said Kourrich ◽  
...  
Keyword(s):  
Rat Brain ◽  
Binding Sites ◽  
Scorpion Toxin ◽  
K Channel ◽  
Pharmacological Characterization ◽  
Toxin Binding ◽  
New Class ◽  
Type K

scholarly journals Binding of scorpion toxin to receptor sites associated with sodium channels in frog muscle. Correlation of voltage-dependent binding with activation.

1979 ◽  
Vol 74 (3) ◽  
pp. 375-391 ◽  
Author(s):  
W A Catterall
Keyword(s):  
Sodium Channels ◽  
Voltage Dependence ◽  
Binding Capacity ◽  
Specific Binding ◽  
Frog Muscle ◽  
Scorpion Toxin ◽  
Sartorius Muscle ◽  
Single Class ◽  
Bathing Medium ◽  
Toxin Binding

Purified scorpion toxin (Leiurus quinquestriatus) slows inactivation of sodium channels in frog muscle at concentrations in the range of 17-170 nM. Mono[125I]iodo scorpion toxin binds to a single class of sites in frog sartorius muscle with a dissociation constant of 14 nM and a binding capacity of 13 fmol/mg wet weight. Specific binding is inhibited more than 90% by 3 microM sea anemone toxin II and by depolarization with 165 mM K+. Half-maximal inhibition of binding is observed on depolarization to -41 mV. The voltage dependence of scorpion toxin binding is correlated with the voltage dependence of activation of sodium channels. Removal of calcium from the bathing medium shifts both activation and inhibition of scorpion toxin binding to more negative membrane potentials. The results are considered in terms of the hypothesis that activation of sodium channels causes a conformational change in the scorpion toxin receptor site resulting in reduced affinity for scorpion toxin.

The binding of tritiated tetrodotoxin to squid giant axons

1975 ◽  
Vol 270 (908) ◽  
pp. 349-352 ◽  
Keyword(s):  
Sodium Channels ◽  
Binding Sites ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
Toxin Concentration ◽  
Giant Axons ◽  
Toxin Binding ◽  
Saturable Binding

The binding of tetrodotoxin to squid giant axons was determined as a function of toxin concentration, using a tritiated toxin preparation of known radiochemical purity and specific activity. From the amount of saturable binding observed, the number of toxin binding sites thought to be sodium channels was found to be 553 ± 119/p.m 2 of axon surface.

scholarly journals Molecular Determinants for Alpha-Scorpion Toxin Binding to the Resting State of a Voltage Sensor of Brain Sodium Channels

2011 ◽  
Vol 100 (3) ◽  
pp. 422a ◽  
Author(s):  
Jinti Wang ◽  
Vladimir Yarov-Yarovoy ◽  
Roy Kahn ◽  
Dalia Gordon ◽  
Michael Gurevitz ◽  
...  
Keyword(s):  
Sodium Channels ◽  
Resting State ◽  
Voltage Sensor ◽  
Scorpion Toxin ◽  
Toxin Binding ◽  
Molecular Determinants

Electron Probe Analysis of Muscle

1982 ◽  
Vol 40 ◽  
pp. 398-401
Author(s):  
A. V. Somlyo ◽  
H. Shuman ◽  
A. P. Somlyo
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Resting State ◽  
Binding Sites ◽  
Electron Probe ◽  
Frog Skeletal Muscle ◽  
Electron Probe Analysis ◽  
Probe Analysis

Electron probe analysis of frozen dried cryosections of frog skeletal muscle, rabbit vascular smooth muscle and of isolated, hyperpermeab1 e rabbit cardiac myocytes has been used to determine the composition of the cytoplasm and organelles in the resting state as well as during contraction. The concentration of elements within the organelles reflects the permeabilities of the organelle membranes to the cytoplasmic ions as well as binding sites. The measurements of [Ca] in the sarcoplasmic reticulum (SR) and mitochondria at rest and during contraction, have direct bearing on their role as release and/or storage sites for Ca in situ.

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