2017/12/12 by Liwei Zhang, Zhang, Liwei, Bob Eisenberg +3
Engineering · Physics and Astronomy · #FOS: Biological sciences #Nanopore and Nanochannel Transport Studies #Quantitative Methods (q-bio.QM) #Quantum, superfluid, helium dynamics #Spectroscopy and Quantum Chemical Studies
paper · pdf · doi:10.48550/arxiv.1712.06666
openalex publication_date 2017/12/12 · openalex created_date 2018/01/05 · openalex updated_date 2026/07/28
In this work, we examine effects of large permanent charges on ionic flow through ion channels based on a quasi-one dimensional Poisson-Nernst-Planck model. It turns out large positive permanent charges inhibit the flux of cation as expected, but strikingly, as the transmembrane electrochemical potential for anion increases in a particular way, the flux of anion decreases. The latter phenomenon was observed experimentally but the cause seemed to be unclear. The mechanisms for these phenomena are examined with the help of the profiles of the ionic concentrations, electric fields and electrochemical potentials. The underlying reasons for the near zero flux of cation and for the decreasing flux of anion are shown to be different over different regions of the permanent charge. Our model is oversimplified. More structural detail and more correlations between ions can and should be included. But the basic finding seems striking and important and deserving of further investigation.