Year: 2014
Type: article
Abstract: In this work, we present a quantum transport model for the selectivity filter in the KcsA potassium ion channel. This model is fully consistent with the fact that two conduction pathways are involved in the translocation of ions thorough the filter, and we show that the presence of a second path may actually bring advantages for the filter as a result of quantum interference. To highlight interferences and resonances in the model, we consider the selectivity filter to be driven by a controlled time-dependent external field which changes the free energy scenario and consequently the conduction of the ions. In particular, we demonstrate that the two-pathway conduction mechanism is more advantageous for the filter when dephasing in the transient configurations is lower than in the main configurations. As a matter of fact, K$^+$ ions in the main configurations are highly coordinated by oxygen atoms of the filter backbone and this increases noise. Moreover, we also show that, for a wide range of dephasing rates and driving frequencies, the two-pathway conduction used by the filter leads indeed to higher ionic currents when compared with the single path model.
Authors: A A Cifuentes, F L Semião
Institution: Universidade Federal do ABC
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Awards: G5979248317, G8328700524
OpenAlex ID: W2099315322