Water movement during permeation process in CiHv1 channel

H2O is responsible for H+ transfer and conduction. The most accepted mechanism for explaining H+ mobility is the Grotthuss model, which proposes fast protonation and deprotonation reactions between H2O molecules along a H-bond network. Thus, protonation and the H+ transport are phenomena that cannot be separated from the study of H2O within a system. In particular, the Hv1 channel, is a protein whose permeation mechanism remains unclear. One hypothesis implicates a H2O wire along the permeation pathway where all H2O molecules point their dipole in the same direction, where H+ jumps between the H-bonds without residue protonation (similar to Grotthuss model), while another proposes that H+ conduction occurs in a H2O cable interrupted by the interaction between the selectivity filter (aspartate) and the 2nd or 3rd arginine of the voltage sensor, where the aspartate is protonated to complete the wire. However, studying the permeation process and how it relates to H2O transport need more precise structural evidence. In this work, we found that unitary conductance was modified in different CiHv1 N264 mutants, but no its proton selectivity. In these mutants by MD, we studied the hydration profile, H2O dipole configurations, H2O flux and the electrostatic profile. Interestingly, the super-conductive N264E construct have favorable electrostatic profile for H+ conduction and favors H2O flux, while low-conductive N264R have an unfavorable electrostatic profile for H+ conduction with a very low probability to find water molecules near to selectivity filter (dry zone). Our results indicate the existence of a wet zone around to N264, suggesting H+ flows in a water continuum possibly combined, with protonation of some residues along permeation pathway. Interestingly, this conduction occurs in a non-grotthuss model manner, according to our dipole configuration profile obtained, suggesting a different mechanism that those previously proposed.