A critique of the capacitor-based "Transmembrane Electrostatically Localized Proton" hypothesis

Abstract

In his Transmembrane Electrostatically Localized Proton hypothesis (TELP), James W. Lee has modeled the bioenergetic membrane as a simple capacitor. According to this model, the surface concentration of protons is completely independent of proton concentration in the bulk phase, and is linearly proportional to the transmembrane potential. Such a proportionality runs counter to the results of experimental measurements, molecular dynamics simulations, and electrostatics calculations. We show that the TELP model dramatically overestimates the surface concentration of protons, and we discuss the electrostatic reasons why a simple capacitor is not an appropriate model for the bioenergetic membrane.

Keywords: Bioenergetics; Chemiosmotic theory; Interfacial partitioning; Proton electrochemical potential; Proton gradient; Protonmotive force; Surface-localized protons.