Physics of ionic conduction in narrow biological and artificial channels

McClintock, Peter V. E. and Luchinsky, Dmitry (2021) Physics of ionic conduction in narrow biological and artificial channels. Entropy, 23 (6). ISSN 1099-4300

Text (flyer_physics_Ionchannels)
flyer_physics_Ionchannels.pdf - Published Version
Download (99kB)

Abstract

Biological ion channels are essential to life in all its forms. The key properties underlying their function are those of selectivity and conductivity—the ability to select between different kinds of ions, while allowing the favoured species to pass at nearly the rate of free diffusion. It is now appreciated that an understanding of selective conduction requires physics, and that the physics of biological ion channels has a great deal in common with that of artificial nanopores. In each case, there are intriguing analogies with the physics of quantum dots. Discovery of the atomic structures of many channels has brought significant progress, as has the building of subnanometer artificial channels and the experimental investigation of their selectivity and conduction; large-scale molecular dynamics simulations are yielding atomistic and statistical insights into many channel properties as a function of structure. However, the ability to predict the function of a channel from its structure, e.g., following a point mutation of a biological channel or the functionalization of a nanopore, remains elusive. Nonetheless, these recent advances have brought us tantalisingly close to a fundamental theory of ionic permeation, based on the statistical physics of ions within the channel. It promises to resolve the long-standing structure–function problem, thus enabling explicit current calculations for relatively complex structures. The Special Issue aims to bring together original high-quality papers on ionic permeation through narrow water-filled channels, both biological and artificial. It will include papers on the statistical physics of the process, on molecular dynamics and Brownian dynamics simulations, and on relevant experiments. The time is ripe for bringing these mutually complementary approaches together, and we anticipate that they will facilitate major breakthroughs enabling the design of nanopores to meet particular technological requirements as well as improvements in drug design.