Detergent extraction of a presumptive gating component from the voltage-dependent sodium channel
Autor: | W J Culp, D T McKenzie |
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Rok vydání: | 1981 |
Předmět: |
Octoxynol
Leiurus Detergents Neurotoxins Scorpion Venoms Gating Ion Channels Polyethylene Glycols law.invention law Animals Neurotoxin Electric Organ Multidisciplinary Chromatography biology Chemistry Sodium channel Cell Membrane Sodium biology.organism_classification Dissociation constant Kinetics Membrane Electrophorus Torpedo Research Article Protein Binding |
Zdroj: | Proceedings of the National Academy of Sciences. 78:7171-7175 |
ISSN: | 1091-6490 0027-8424 |
DOI: | 10.1073/pnas.78.11.7171 |
Popis: | A physiologically characterized radiolabeled neurotoxin complex obtained from venom of the scorpion Leiurus quinquestriatus has been used to identify detergent-solubilized presumptive sodium channel components in sucrose gradients. This toxin-binding component is found in extracts prepared from three sources of excitable membrane but appears to be absent from similar extracts prepared from nonexcitable membrane or from Torpedo californica membrane. Procedures that destroy the physiological activity of the Leiurus neurotoxin lead to a corresponding loss of toxin binding to the putative sodium channel component. The major component recognized by the Leiurus toxin sediments at 6.5 S. Scatchard analysis of quantitative binding experiments carried out in sucrose gradients shows approximately linear plots and indicates that the toxin recognizes a relatively small number of sites with a dissociation constant near 10 nM. Once formed, the channel element--toxin complex is quite stable. Experiments show diphasic dissociation kinetics with half-times near 70 hr and greater than 200 hr. |
Databáze: | OpenAIRE |
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