Permeation and gating of α1 glycine‐gated channels expressed at low and high density in Xenopus oocyte

FEBS Letters

Maammar, Mohammed¹  Rodeau, Jean-Luc¹  Taleb, Omar¹ 

[1] Laboratoire de Neurobiologie Cellulaire, UPR CNRS 9009, 5 rue Blaise Pascal, F- 67084 Strasbourg, France

关键词: Glycine-gated channel;    α1-Subunit formed homo-oligomeric channel;    Anion channel;    EC50;    half-maximal effective concentration;    GlyR;    glycine receptor;    GlyR channel;    glycine-gated channel;   

DOI  :  10.1016/S0014-5793(97)00986-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

When a high density of α1-subunit glycine receptor (GlyR) is expressed in Xenopus oocytes, two populations of channels can be distinguished according to their apparent affinity for glycine which differs 5- to 6-fold. To compare the open pore diameter of these channels, the relative permeability of formate with respect to chloride (P _formate/P _Cl) was determined in bionic conditions. For the low-affinity GlyR P _formate/P _Cl was comparable to that reported for glycine-gated channels in cultured spinal cord and hippocampal neurons. In contrast, the high-affinity GlyR had a 56% larger P _formate/P _Cl. In addition, the open probability of the channels was differentially sensitive to voltage. These results show that the high expression of α1 GlyR resulted in two populations of GlyR which differed not only in the affinity to agonists but also in permeation and gating mechanisms.

【 授权许可】

Unknown