(694c) Dipole Oriented Water Wires Confined in Artificial Chiral Membrane Channels

Authors: 
Kocsis, I., Institut Europeen des Membranes
Belfort, G., Rensselaer Polytechnic Institute
Sorci, M., Rensselaer Polytechnic Institute
Licsandru, E., 2Institut Europeen des Membranes
Legrand, Y. M., Institut Européen des Membranes
van der Lee, A., Institut Européen des Membranes
Petersen, P., Cornell University
Barboiu, M., Institut Européen des Membranes
Aquaporins (AQPs) are known for their highly selective water transport through cell membranes. Oriented water-wires spanning the AQPs pore is of considerable importance for the selective translocation of water over ions. We recently discovered that water translocation through artificial I-quartets (self-assembled imidazole structures) increases when water molecules display dipolar orientation. Here, we show that water confined inside self-assembled I-quartets integrated into supported lipid bilayers (SLB) form oriented water-wires exhibiting a chiral super-structure, as visualized with static solid state X-ray single-crystal structures and sum-frequency generation (SFG) spectroscopy. The integration and assembly of I-quartets into SLB were also monitored with a Quartz Crystal Microbalance with Dissipation (QCM-D) and modeled with molecular simulations in order to provide physical insight into dipolar water orientation within artificial I-quartet channels. This study provides the first experimental proof of dipole orientated water wires within artificial water channels inserted in bilayer membranes and the characterization of their hydrogen-bond connectivity and chiral alignment. Uncovering the interplay between the hydrogen-bonded water structure and water transport through the self-assembled i-quartets is critical to understanding the function of natural membrane channels and will guide the design principles for developing artificial water channels for water purification.