Molecular modeling of voltage-gated potassium channel pore.
Zhongguo Yao Li Xue Bao
; 18(4): 323-30, 1997 Jul.
Article
em En
| MEDLINE
| ID: mdl-10072914
ABSTRACT
AIM:
To build a structure model for the pore of voltage-gated Shaker potassium channel and examine its validity.METHODS:
(1) Structural restraints were derived from experimental and theoretical studies; (2) An initial structural motif satisfying the derived restraints was first constructed, and further refined by restrained molecular mechanics; (3) The quality of the model was judged by the criterion that whether it could clarify molecular mechanisms of channel functions and explain the known experimental facts.RESULTS:
(1) A computer pore structure was proposed, in which the residues within signature sequence (corresponding to Shaker 439-446) dipped into the membrane and formed the narrow part of the pore in a non-periodic conformation, while the other residues in the P region constituted the outer mouth of the pore; (2) The ion selectivity was achieved through cation-pi orbital interaction mechanism at position 445 and oxygen cage mechanism at position 447; (3) Different binding modes led to different affinity of CTX and AgTx2 to channel; and (4) The inside of pore was dominated by negative electrostatic potential.CONCLUSION:
The model proposed was consistent with the derived restraints from the experimental results.
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Base de dados:
MEDLINE
Assunto principal:
Canais de Potássio
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
1997
Tipo de documento:
Article