Theoretical modelling of anion transport in liposomes: electrogenic anion exchange as a new paradigm in supramolecular chemistry

Abstract

We describe an application of the Goldman–Hodgkin–Katz (GHK) theory and kinetic modelling to study the function of the anion transporters in liposomes. The study is based on a concept, which has not yet been comprehensively explored within the field, that the low-turnover anion transporters initiate electrogenic exchange across biomembrane. We have devised an analytical description for two compounds, cationic and electroneutral, constructed flowchart-based kinetic models and solved the transport equations numerically. To our knowledge, the function of the small molecules, which selectively increases the anion permeability of a bilayer, has never been examined using this technique. The findings illustrate that the GHK-based kinetic modelling, easily available in organic laboratory by means of commercially available differential equation solvers, is an essential tool, which aims to complement the experiential studies. The application of theory affects fundamental understanding of the phenomena, providing an alternative way to address questions about mechanism and selectivity of the small molecules, which have been raised in the field. In particular, it aims to facilitate the search for anionophores that are selective for a specific inorganic anion. ‘Valinomycin for anions’ will find numerous applications, ranging from carrier-based ion-selective electrodes to a new tool for transport studied in the living cells and a potential treatment for the anion transport disorders such as cystic fibrosis.