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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
21
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pubmed:dateCreated |
1985-10-30
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pubmed:abstractText |
Purified sodium channels incorporated into phosphatidylcholine (PC) vesicles mediate neurotoxin-activated 22Na+ influx but do not bind the alpha-scorpion toxin from Leiurus quinquestriatus (LqTx) with high affinity. Addition of phosphatidylethanolamine (PE) or phosphatidylserine to the reconstitution mixture restores high affinity LqTx binding with KD = 1.9 nM for PC/PE vesicles at -90 mV and 36 degrees C in sucrose-substituted medium. Other lipids tested were markedly less effective. The binding of LqTx in vesicles of PC/PE (65:35) is sensitive to both the membrane potential formed by sodium gradients across the reconstituted vesicle membrane and the cation concentration in the extravesicular medium. Binding of LqTx is reduced 3- to 4-fold upon depolarization to 0 mV from -50 to -60 mV in experiments in which [Na+]out/[Na+]in is varied by changing [Na+]in or [Na+]out at constant extravesicular ionic strength. It is concluded that the purified sodium channel contains the receptor site for LqTx in functional form and that restoration of high affinity, voltage-dependent binding of LqTx by the purified sodium channel requires an appropriate ratio of PC to PE and/or phosphatidylserine in the vesicle membrane.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Cations,
http://linkedlifedata.com/resource/pubmed/chemical/Iodine Radioisotopes,
http://linkedlifedata.com/resource/pubmed/chemical/Ion Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Phospholipids,
http://linkedlifedata.com/resource/pubmed/chemical/Scorpion Venoms,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium
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pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
25
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pubmed:volume |
260
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
11542-7
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2413014-Animals,
pubmed-meshheading:2413014-Brain,
pubmed-meshheading:2413014-Cations,
pubmed-meshheading:2413014-Iodine Radioisotopes,
pubmed-meshheading:2413014-Ion Channels,
pubmed-meshheading:2413014-Kinetics,
pubmed-meshheading:2413014-Membrane Potentials,
pubmed-meshheading:2413014-Phospholipids,
pubmed-meshheading:2413014-Rats,
pubmed-meshheading:2413014-Scorpion Venoms,
pubmed-meshheading:2413014-Sodium
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pubmed:year |
1985
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pubmed:articleTitle |
The sodium channel from rat brain. Reconstitution of voltage-dependent scorpion toxin binding in vesicles of defined lipid composition.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.
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