Here we describe the basic features of the interaction of K+ channels with Pi1, a recently described 35 amino acid scorpion toxin, which has four disulfide bridges instead of the three commonly found in all the other known scorpion toxins. We found that: (a) Pi1 blocks ShakerB from the outside with a 1:1 stoichiometry, and a Kd of 32 nM in zero external [K+]; (b) extracellular K+, Rb+ and Cs+ but not NH4+ ions strongly impede (destabilize) the block by this toxin; interestingly (c) the destabilizing binding of K+, Rb+, and Cs+ is described by a Hill coefficient n > 1; (d) external K+ is more effective than internal K+ to reduce the block by Pi1.
| Predicate | Object |
|---|---|
| rdf:type | |
| rdfs:comment |
Here we describe the basic features of the interaction of K+ channels with Pi1, a recently described 35 amino acid scorpion toxin, which has four disulfide bridges instead of the three commonly found in all the other known scorpion toxins. We found that: (a) Pi1 blocks ShakerB from the outside with a 1:1 stoichiometry, and a Kd of 32 nM in zero external [K+]; (b) extracellular K+, Rb+ and Cs+ but not NH4+ ions strongly impede (destabilize) the block by this toxin; interestingly (c) the destabilizing binding of K+, Rb+, and Cs+ is described by a Hill coefficient n > 1; (d) external K+ is more effective than internal K+ to reduce the block by Pi1.
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| skos:exactMatch | |
| uniprot:name |
FEBS Lett.
|
| uniprot:author |
Gomez-Lagunas F.,
Olamendi-Portugal T.,
Possani L.D.
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| uniprot:date |
1997
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| uniprot:pages |
197-200
|
| uniprot:title |
Block of ShakerB K+ channels by Pi1, a novel class of scorpion toxin.
|
| uniprot:volume |
400
|
| dc-term:identifier |
doi:10.1016/S0014-5793(96)01387-7
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