Coupling mechanisms in ATP synthesis: Rejoinder to "Response to molecular-level understanding of biological energy coupling and transduction"

Abstract

Recently, an exchange of views on key fundamental aspects of biological energy coupling and ATP synthesis in the vital process of oxidative phosphorylation appeared in the pages of this journal. The very difficult scientific problems are analyzed and clarified. Errors in the mathematical/thermodynamic equations of a previous analysis have been identified that invalidate previous assertions, and the correct equations are derived. The major differences between the two competing models - localized versus delocalized - for biological energy coupling and transduction are discussed from physical, chemical, and mathematical perspectives. The opposing views are summarized, so that the reader can assess for himself or herself the merits of the two coupling mechanisms. A fresh attempt has been made to go to the root of bioenergetics by calculating the desolvation free energy barrier, ∆G_desolvation for ion transport across biomembranes. Several constructive suggestions are made that have the power to resolve the basic contradictions and the areas of fundamental conflict, and reach a consensus by catalyzing the progress of future research in this interdisciplinary field.

Keywords: ATP synthase; Bioenergetics; Coupling mechanisms; Delocalized model of coupling; Desolvation free energy; Localized model of coupling; Mitchell's chemiosmotic theory; Mitochondria; Nath's torsional mechanism of energy transduction and ATP synthesis; Nath's two-ion theory of energy coupling; Oxidative phosphorylation; Proton translocation across biological membranes.