  It has been suggested that quantum coherence in the selectivity filter of ion
channel may play a key role in fast conduction and selectivity of ions.
However, it has not been clearly elucidated yet why classical coherence is not
sufficient for this purpose. In this paper, we investigate the classical
vibrational coherence between carbonyl groups oscillations in the selectivity
filter of KcsA ion channels based on the data obtained from molecular dynamics
simulations. Our results show that classical coherence plays no effective role
in fast ionic conduction.
