New binding site on common molecular scaffold provides HERG channel specificity of scorpion toxin BeKm-1.
J Biol Chem
; 277(45): 43104-9, 2002 Nov 08.
Article
em En
| MEDLINE
| ID: mdl-12151390
ABSTRACT
The scorpion toxin BeKm-1 is unique among a variety of known short scorpion toxins affecting potassium channels in its selective action on ether-a-go-go-related gene (ERG)-type channels. BeKm-1 shares the common molecular scaffold with other short scorpion toxins. The toxin spatial structure resolved by NMR consists of a short alpha-helix and a triple-stranded antiparallel beta-sheet. By toxin mutagenesis study we identified the residues that are important for the binding of BeKm-1 to the human ERG K+ (HERG) channel. The most critical residues (Tyr-11, Lys-18, Arg-20, Lys-23) are located in the alpha-helix and following loop whereas the "traditional" functional site of other short scorpion toxins is formed by residues from the beta-sheet. Thus the unique location of the binding site of BeKm-1 provides its specificity toward the HERG channel.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Venenos de Escorpião
/
Canais de Potássio
/
Transativadores
/
Canais de Potássio de Abertura Dependente da Tensão da Membrana
/
Proteínas de Transporte de Cátions
/
Proteínas de Ligação a DNA
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2002
Tipo de documento:
Article
País de afiliação:
Federação Russa