Chemical substitutions in the selectivity filter of potassium channels do not rule out constricted-like conformations for C-type inactivation.

ABSTRACT: In many K⁺ channels, prolonged activating stimuli lead to a time-dependent reduction in ion conduction, a phenomenon known as C-type inactivation. X-ray structures of the KcsA channel suggest that this inactivated state corresponds to a "constricted" conformation of the selectivity filter. However, the functional significance of the constricted conformation has become a matter of debate. Functional and structural studies based on chemically modified semisynthetic KcsA channels along the selectivity filter led to the conclusion that the constricted conformation does not correspond to the C-type inactivated state. The main results supporting this view include the observation that C-type inactivation is not suppressed by a substitution of D-alanine at Gly77, even though this modifi

SUBMITTER: Li J 

PROVIDER: S-EPMC5651753 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature