Resonance-Driven Mechanisms of Ion Transport and Selectivity

Abstract

Ion channels selectively transport ions, yet the underlying mechanisms remain elusive. We propose a physical model based on the Driven Damped Harmonic Oscillator (DDHO), where self-organizing turbulent structures in the ionic flow generate oscillating pressure waves and toroidal vortices. These structures drive aqua-ions into resonance, facilitating the shedding of hydration shells and enabling ion permeation as free ions. To capture the spatiotemporal complexity of this process, we develop a macroscopic continuum model integrating the Navier--Stokes equations, Gauss's law, and convection-diffusion dynamics. Numerical simulations reveal strong oscillations that drive dehydration and ionic jet formation, supporting the DDHO mechanism. Model predictions closely match patch-clamp experimental data. The DDHO framework predicts a frequency-dependent resonance response, effectively acting as a selective filter. Applied to experimental data, the model reveals distinct separation between ion species and hydration states, quantified by a high Mahalanobis distance and oscillator quality factor. Furthermore, the model provides insight into the effects of single nucleotide polymorphisms (SNPs) on ion selectivity. Mutations that alter channel geometry shift resonance peaks, disrupting selective transport and potentially leading to genetic disorders.