Ionic Conductivity Along Transmembrane-Electropores In Human Aquaporin 4: Calcium Effects From Non-Equilibrium Molecular Dynamics

Electroporation is subject to extensive research efforts and is a rather under-studied in trans-membrane proteins, particularly considering promising possible applications in biotechnology and medicine. In particular, some such innovative potential applications are centred on controlling the permeability of ions through electro-pores. Here, we study ions' conductivity along metastable electro-pores across h-AQP4 as a typical case study of conduction of ions across membranes; of note, we are achieving a good degree of control over this permeation in the presence of calcium ions on either side of the membrane. In this work we will unveil the effect of polyvalent calcium cations, compared to that of sodium cations, onto the biological system. We also assess ions' in-electropore residence-time and mean-first-passage-time distributions and determine ionic-conductivity estimates similar to water in other nano-confined milieux.