A strongly interacting pair of residues on the contact surface of charybdotoxin and a Shaker K+ channel

Naranjo, D; Miller, C


Charybdotoxin, a peptide neurotoxin of known molecular structure, blocks Shaker K+ channels by binding to a receptor at the outer opening of the ion conduction pathway. Analysis of variants of CTX at position 29 and of Shaker at position 449 shows that these two residues interact closely in the channel-toxin complex. The CTX mutation M29I leads to a slight strengthening of block when tested on Shaker-449T; the same CTX mutation weakens block 1700-fold when tested on Shaker-449F. The known position of CTX-29 on the toxin's interaction surface thus locates Shaker-449 within 5 Angstrom of the pore axis of the closed channel. All four subunits must carry the 449F mutation to produce a highly toxin-insensitive channel.

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Título según WOS: ID WOS:A1996TT30700015 Not found in local WOS DB
Título de la Revista: NEURON
Volumen: 16
Número: 1
Editorial: Cell Press
Fecha de publicación: 1996
Página de inicio: 123
Página final: 130


Notas: ISI