Molecular Events behind the Selectivity and Inactivation Properties of Model NaK-Derived Ion Channels.

ABSTRACT: Y55W mutants of non-selective NaK and partly K⁺-selective NaK2K channels have been used to explore the conformational dynamics at the pore region of these channels as they interact with either Na⁺ or K⁺. A major conclusion is that these channels exhibit a remarkable pore conformational flexibility. Homo-FRET measurements reveal a large change in W55-W55 intersubunit distances, enabling the selectivity filter (SF) to admit different species, thus, favoring poor or no selectivity. Depending on the cation, these channels exhibit wide-open conformations of the SF in Na⁺, or tight induced-fit conformations in K⁺, most favored in the four binding sites containing NaK2K channels. Such conformational flexibility seems to arise from an altered

SUBMITTER: Giudici AM 

PROVIDER: S-EPMC9409022 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature