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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1980-4-23
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pubmed:abstractText |
Extracts prepared from heads of Drosophila melanogaster show high-affinity binding (KD = 1.9 nM) of [3H]saxitonin, a compound known to bind to and block voltage-sensitive sodium channels in other organisms. The interaction between saxitoxin and the Drosophila saxitoxin receptor is non-cooperative and reversible with a half-life of 18.3 s for binding at 4 degrees C. The saturable binding is specifically inhibited by tetrodotoxin with a K1 = 0.30 nM. The number of saturable binding sites in the extract is 97 fmol/mg protein. Since approx. 50% of the binding activity is recovered in the extract, the number of binding sites in the head is estimated to be 6.4 fmol/mg head. Nerve conduction in Drosophila larvae is completely blocked after 20 min in a bathing solution containing 200 nM tetrodotoxin. A comparison between the binding and the electrophysiological studies in Drosophila and other organisms suggests that the Drosophila saxitoxin receptor is part of the voltage-sensitive sodium channel involved in the propagation of action potentials. A mutant (ttxs), which is abnormally sensitive to dietary tetrodotoxin, is shown to be indistinguishable from wild type with respect to [3H]saxitonin-binding properties and physiological sensitivity to tetrodotoxin. These studies provide techniques which can be used to identify mutants with defects in the saxitoxin-binding component of the sodium channel.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Jan
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pubmed:issn |
0006-3002
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
25
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pubmed:volume |
595
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
291-303
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:6766315-Animals,
pubmed-meshheading:6766315-Binding, Competitive,
pubmed-meshheading:6766315-Drosophila melanogaster,
pubmed-meshheading:6766315-Ion Channels,
pubmed-meshheading:6766315-Kinetics,
pubmed-meshheading:6766315-Larva,
pubmed-meshheading:6766315-Neuromuscular Junction,
pubmed-meshheading:6766315-Saxitoxin,
pubmed-meshheading:6766315-Synapses,
pubmed-meshheading:6766315-Tetrodotoxin
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pubmed:year |
1980
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pubmed:articleTitle |
Saxitoxin binding to sodium channels in head extracts from wild-type and tetrodotoxin-sensitive strains of Drosophila melanogaster.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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