Voltage dependent modification of sodium channel gating with water-soluble carbodiimide

1986 ◽  
Vol 406 (1) ◽  
pp. 31-36 ◽  
Author(s):  
G. N. Mozhayeva ◽  
A. P. Naumov ◽  
E. D. Nosyreva
Keyword(s):  
Sodium Channel ◽  
Channel Gating ◽  
Water Soluble ◽  
Voltage Dependent ◽  
Dependent Modification

Effects of water-soluble carbodiimide on "fast" sodium channel gating in the rat sensory neuron membrane

1987 ◽  
Vol 19 (1) ◽  
pp. 39-44
Author(s):  
A. P. Naumov ◽  
Yu. A. Negulyaev ◽  
E. A. Vedernikova
Keyword(s):  
Sodium Channel ◽  
Sensory Neuron ◽  
Channel Gating ◽  
Water Soluble ◽  
Neuron Membrane

scholarly journals Movement and Crevices Around a Sodium Channel S3 Segment

2002 ◽  
Vol 120 (3) ◽  
pp. 419-436 ◽  
Author(s):  
Thao P. Nguyen ◽  
Richard Horn
Keyword(s):  
Electric Field ◽  
Sodium Channel ◽  
Uv Irradiation ◽  
Sulfhydryl Reagents ◽  
Transmembrane Segments ◽  
Translational Movement ◽  
Accessible Region ◽  
Voltage Dependent ◽  
S3 Segment ◽  
Dependent Modification

Voltage sensing is due mainly to the movement of positively charged S4 segments through the membrane electric field during changes of membrane potential. The roles of other transmembrane segments are under study. The S3 segment of domain 4 (D4/S3) in the sodium channel Nav1.4 carries two negatively charged residues and has been implicated in voltage-dependent gating. We substituted cysteines into nine putative “high impact” sites along the complete length of D4/S3 and evaluated their accessibilities to extracellular sulfhydryl reagents. Only the four outermost substituted cysteines (L1433C, L1431C, G1430C, and S1427C) are accessible to extracellular sulfhydryl reagents. We measured the voltage-dependent modification rates of the two cysteines situated at the extreme ends of this accessible region, L1433C and S1427C. Independent of the charge on the sulfhydryl reagents, depolarization increases the reactivity of both of these residues. Thus, the direction of the voltage dependence is opposite to that expected for a negatively charged voltage sensor, namely an inward translational movement in response to depolarization. Intrinsic electrostatic potentials were probed by charged sulfhydryl reagents and were either negative or positive, respectively, near L1433C and S1427C. The magnitude of the electrostatic potential near S1427C decreases with depolarization, suggesting that the extracellular crevice next to it widens during depolarization. S1427C experiences 44% of the electric field, as probed by charged cysteine reagents. To further explore movements around D4/S3, we labeled cysteines with the photoactivatable cross-linking reagent benzophenone-4-carboxamidocysteine methanethiosulfonate and examined the effects of UV irradiation on channel gating. After labeling with this reagent, all accessible cysteine mutants show altered gating upon brief UV irradiation. In each case, the apparent insertion efficiency of the photoactivated benzophenone increases with depolarization, indicating voltage-dependent movement near the extracellular end of D4/S3.

scholarly journals Calcium-Mediated Tailspin of Calmodulin on the IQ Motif of the Neuronal Voltage-Dependent Sodium Channel Nav1.2

2013 ◽  
Vol 104 (2) ◽  
pp. 14a ◽  
Author(s):  
Madeline A. Shea ◽  
Mark S. Miller ◽  
Jesse B. Yoder ◽  
C. Andrew Fowler ◽  
Michael D. Feldkamp ◽  
...  
Keyword(s):  
Sodium Channel ◽  
Iq Motif ◽  
Voltage Dependent

Primary structure of the adult human skeletal muscle voltage-dependent sodium channel

1992 ◽  
Vol 31 (2) ◽  
pp. 131-137 ◽  
Author(s):  
Alfred L. George ◽  
Jeffrey Komisarof ◽  
Roland G. Kallen ◽  
Robert L. Barchi
Keyword(s):  
Skeletal Muscle ◽  
Sodium Channel ◽  
Primary Structure ◽  
Human Skeletal Muscle ◽  
Adult Human ◽  
Voltage Dependent
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