Na+ block and permeation in a K+ channel of known structure |
| |
Authors: | Nimigean Crina M Miller Christopher |
| |
Affiliation: | Department of Biochemistry, Howard Hughes Medical Institute, Brandeis University, Waltham, MA 02454, USA. |
| |
Abstract: | The effects of intracellular Na(+) were studied on K(+) and Rb(+) currents through single KcsA channels. At low voltage, Na(+) produces voltage-dependent block, which becomes relieved at high voltage by a "punchthrough" mechanism representing Na(+) escaping from its blocking site through the selectivity filter. The Na(+) blocking site is located in the wide, hydrated vestibule, and it displays unexpected selectivity for K(+) and Rb(+) against Na(+). The voltage dependence of Na(+) block reflects coordinated movements of the blocker with permeant ions in the selectivity filter. |
| |
Keywords: | selectivity KCSA punchthrough |
本文献已被 PubMed 等数据库收录! |
|