Influence of extracellular monovalent cations on pore and gating properties of P2X7 receptor-operated single-channel currents.

ABSTRACT: Using the patch-clamp method, we studied the influence of external alkali and organic monovalent cations on the single-channel properties of the adenosine triphosphate (ATP)-activated recombinant human P2X(7) receptor. The slope conductance of the hP2X(7) channel decreased and the reversal potential was shifted to more negative values as the ionic diameter of the organic test cations increased. From the relationship between single-channel conductance and the dimensions of the inward current carrier, the narrowest portion of the pore was estimated to have a mean diameter of approximately 8.5 A. Single-channel kinetics and permeation properties remained unchanged during receptor activation by up to 1 mM ATP(4-) for >1 min, arguing against a molecular correlate of pore dilation at the single

SUBMITTER: Riedel T 

PROVIDER: S-EPMC1913143 | biostudies-literature | 2007 Aug

REPOSITORIES: biostudies-literature