A SIMPLE-MODEL FOR SURFACE-CHARGE ON ION-CHANNEL PROTEINS

NARANJO, D; LATORRE, R; CHERBAVAZ, D; MCGILL, P; SCHUMAKER, MF

Abstract

We present a simple two-parameter model for surface charge directly associated with ion channels. A spherically symmetric ''charged shell'' models a distribution of surface charge arrayed about the channel entrance, with a corresponding set of image charges behind the plane of the membrane. The transition between a regime of buffered conductance and a regime of rapidly falling conductance at very low ionic strength is found to depend on the magnitude of the surface charge as well as the separation between the charge and the channel entrance. This resolves an apparent discrepancy between the experimental findings of Naranjo and Latorre (1993. Biophys. J. 64:1038-1050) and previous theoretical computations. The charged-shell model is used in a comparative study of the toad skeletal muscle conductance data of Naranjo and Latorre, the rat skeletal muscle conductances of Ravindran et al. (1992. Biophys. J. 61:494-508), and a second set of rat muscle conductances presented in this paper.

Más información

Título según WOS: ID WOS:A1994MP04100007 Not found in local WOS DB
Título de la Revista: BIOPHYSICAL JOURNAL
Volumen: 66
Número: 1
Editorial: Cell Press
Fecha de publicación: 1994
Página de inicio: 59
Página final: 70
DOI:

10.1016/S0006-3495(94)80750-7

Notas: ISI