Tightly connected water wires facilitate fast proton uptake at the proton entrance of proton pumping proteins.

Tightly connected water wires (TCW) exist in systems with nonconfined water like the solvated membrane proton pump system. The TCWs that connect to the negatively charged proton entrance facilitate the fast proton uptake of the proton pump. They function as a direct proton bridge or/and stabilizer of protons within the Coulomb cage of the proton entrance. Negatively charged residue(s) at the proton entrance induce a large population of long TCWs. Additional negatively charged residues increase the population of such long TCWs and, thus, raise the possibility to capture proton from the solution.