Kinetics of interaction of scorpion toxin with sodium channels in the Ranvier node membrane

1981 ◽  
Vol 12 (6) ◽  
pp. 409-415 ◽  
Author(s):  
G. N. Mozhaeva ◽  
A. P. Naumov
Keyword(s):  
Sodium Channels ◽  
Scorpion Toxin ◽  
Ranvier Node ◽  
Kinetics Of

scholarly journals An excitatory scorpion toxin with a distinctive feature: an additional α helix at the C terminus and its implications for interaction with insect sodium channels

Structure ◽  
1998 ◽  
Vol 6 (9) ◽  
pp. 1095-1103 ◽  
Author(s):  
Deena A Oren ◽  
Oren Froy ◽  
Efrat Amit ◽  
Nurit Kleinberger-Doron ◽  
Michael Gurevitz ◽  
...  
Keyword(s):  
Sodium Channels ◽  
Distinctive Feature ◽  
Scorpion Toxin ◽  
C Terminus ◽  
Α Helix

scholarly journals α-Scorpion Toxin Impairs a Conformational Change that Leads to Fast Inactivation of Muscle Sodium Channels

2008 ◽  
Vol 132 (2) ◽  
pp. 251-263 ◽  
Author(s):  
Fabiana V. Campos ◽  
Baron Chanda ◽  
Paulo S.L. Beirão ◽  
Francisco Bezanilla
Keyword(s):  
Sodium Channels ◽  
Slow Component ◽  
Scorpion Toxin ◽  
Fast Inactivation ◽  
Gating Current ◽  
Voltage Sensors ◽  
Current Decay ◽  
Fluorescence Measurements ◽  
Gating Charge ◽  
Domain Iii

α-Scorpion toxins bind in a voltage-dependent way to site 3 of the sodium channels, which is partially formed by the loop connecting S3 and S4 segments of domain IV, slowing down fast inactivation. We have used Ts3, an α-scorpion toxin from the Brazilian scorpion Tityus serrulatus, to analyze the effects of this family of toxins on the muscle sodium channels expressed in Xenopus oocytes. In the presence of Ts3 the total gating charge was reduced by 30% compared with control conditions. Ts3 accelerated the gating current kinetics, decreasing the contribution of the slow component to the ON gating current decay, indicating that S4-DIV was specifically inhibited by the toxin. In addition, Ts3 accelerated and decreased the fraction of charge in the slow component of the OFF gating current decay, which reflects an acceleration in the recovery from the fast inactivation. Site-specific fluorescence measurements indicate that Ts3 binding to the voltage-gated sodium channel eliminates one of the components of the fluorescent signal from S4-DIV. We also measured the fluorescent signals produced by the movement of the first three voltage sensors to test whether the bound Ts3 affects the movement of the other voltage sensors. While the fluorescence–voltage (F-V) relationship of domain II was only slightly affected and the F-V of domain III remained unaffected in the presence of Ts3, the toxin significantly shifted the F-V of domain I to more positive potentials, which agrees with previous studies showing a strong coupling between domains I and IV. These results are consistent with the proposed model, in which Ts3 specifically impairs the fraction of the movement of the S4-DIV that allows fast inactivation to occur at normal rates.

Electrophysiological characteristics of cloned skeletal and cardiac muscle sodium channels

1996 ◽  
Vol 271 (2) ◽  
pp. H498-H506 ◽  
Author(s):  
M. Chahine ◽  
I. Deschene ◽  
L. Q. Chen ◽  
R. G. Kallen
Keyword(s):  
Steady State ◽  
Sodium Channels ◽  
H Infinity ◽  
Hek 293 ◽  
Human Embryonic Kidney Cells ◽  
Current Decay ◽  
Voltage Gated Sodium Channels ◽  
Recovery From Inactivation ◽  
Steady State Inactivation ◽  
Kinetics Of

The alpha-subunit encoding for voltage-gated sodium channels rSkM1 (rat skeletal muscle subtype 1) and hH1 (human heart subtype 1) has been cloned and expressed by various groups under various conditions in Xenopus oocytes and the tsA201 (HEK 293) mammalian cell line derived from human embryonic kidney cells. In this study, we have expressed hH1 and rSkM1 in tsA201 cells for comparison under the same conditions using patch-clamp methods. Our results show significant differences in the current-voltage (I-V) relationship, kinetics of current decay, voltage dependence of steady-state inactivation, and the time constant for recovery from inactivation. We studied several rSkM1/hH1 chimeric sodium channels to identify the structural regions responsible for the different biophysical behavior of the two channel subtypes. Exchanging the interdomain (ID3-4) loops, thought to contain the inactivation particle, between rSkM1 and hH1 had no effect on the electrophysiological behaviors, including inactivation, indicating that the differences in channel subtype characteristics are determined by parts of the channel other than the ID3-4 segment. The data on a chimeric channel in which D1 and D4 are derived from hH1 while D2 and D3 and the ID1-2, ID2-3, and ID3-4 loops are from rSkM1 show that D1 and/or D4 seem to be responsible for the slower kinetics of inactivation of hH1 while D2 and/or D3 appear to contain the determinants for the differences in the I-V relationship, steady-state inactivation (h infinity) curve, and the kinetics of the recovery from inactivation.

Complex association and dissociation kinetics of brevetoxin binding to voltage-sensitive rat brain sodium channels

2006 ◽  
Vol 4 (6) ◽  
pp. 261-270 ◽  
Author(s):  
Philip L. Whitney ◽  
Daniel G. Baden
Keyword(s):  
Rat Brain ◽  
Sodium Channels ◽  
Dissociation Kinetics ◽  
Kinetics Of

Molecular cloning and functional expression of the alpha-scorpion toxin BotIII: pivotal role of the C-terminal region for its interaction with voltage-dependent sodium channels

Peptides ◽  
2004 ◽  
Vol 25 (2) ◽  
pp. 151-161 ◽  
Author(s):  
Khadija Benkhadir ◽  
Riadh Kharrat ◽  
Sandrine Cestèle ◽  
Amor Mosbah ◽  
Hervé Rochat ◽  
...  
Keyword(s):  
Molecular Cloning ◽  
Sodium Channels ◽  
Functional Expression ◽  
Terminal Region ◽  
Scorpion Toxin ◽  
Pivotal Role ◽  
Voltage Dependent

scholarly journals Bot IT2 : a new scorpion toxin to study receptor site on insect sodium channels

FEBS Letters ◽  
1997 ◽  
Vol 405 (1) ◽  
pp. 77-80 ◽  
Author(s):  
Sandrine Cestèle ◽  
Lamia Borchani ◽  
Mohamed El Ayeb ◽  
Hervé Rochat
Keyword(s):  
Sodium Channels ◽  
Receptor Site ◽  
Scorpion Toxin

Ultrastructural localization of voltage-sensitive sodium channels using [125I]α scorpion toxin

1985 ◽  
Vol 334 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Pierre Cau ◽  
Annick Massacrier ◽  
Jean-Louis Boudier ◽  
Franç¸ois Couraud ◽  
Janine Bottini ◽  
...  
Keyword(s):  
Sodium Channels ◽  
Ultrastructural Localization ◽  
Scorpion Toxin

Effect of Depolarization on Binding Kinetics of Scorpion α-Toxin Highlights Conformational Changes of Rat Brain Sodium Channels†

Biochemistry ◽  
2001 ◽  
Vol 40 (48) ◽  
pp. 14576-14584 ◽  
Author(s):  
Nicolas Gilles ◽  
Enrico Leipold ◽  
Haijun Chen ◽  
Stefan H. Heinemann ◽  
Dalia Gordon
Keyword(s):  
Rat Brain ◽  
Sodium Channels ◽  
Conformational Changes ◽  
Binding Kinetics ◽  
Kinetics Of

Reconstitution of High-Affinity Binding of a β-Scorpion Toxin to Neurotoxin Receptor Site 4 on Purified Sodium Channels

2002 ◽  
Vol 65 (3) ◽  
pp. 1358-1364 ◽  
Author(s):  
William Thomsen ◽  
M. F. Martin-Eauclaire ◽  
Hervé Rochat ◽  
William A. Catterall
Keyword(s):  
Sodium Channels ◽  
Receptor Site ◽  
Scorpion Toxin ◽  
Affinity Binding ◽  
High Affinity Binding ◽  
High Affinity
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