Diffusion model in ion channel gating. Extension to agonist-activated ion channels.
Biophys J
; 59(5): 1136-42, 1991 May.
Article
em En
| MEDLINE
| ID: mdl-1714303
ABSTRACT
Previously, we described a model which treats ion channel gating as a discrete diffusion problem. In the case of agonist-activated channels at high agonist concentration, the model predicts that the closed lifetime probability density function from single channel recording approximates a power law with an exponent of -3/2 (Millhauser, G. L., E. E. Salpeter, and R. E. Oswald. 1988a. Proc. Natl. Acad. Sci. USA. 85 1503-1507). This prediction is consistent with distributions derived from a number of ligand-gated channels at high agonist concentration (Millhauser, G. L., E. E. Salpeter, and R. E. Oswald. 1988b. Biophys. J. 54 1165-1168.) but does not describe the behavior of ion channels at low activator concentrations. We examine here an extension of this model to include an agonist binding step. This extended model is consistent with the closed time distributions generated from the BC3H-1 nicotinic acetylcholine receptor for agonist concentrations varying over three orders of magnitude.
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Ativação do Canal Iônico
/
Receptores Nicotínicos
/
Canais Iônicos
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Biophys J
Ano de publicação:
1991
Tipo de documento:
Article