Coupling in ATP synthesis: Test of thermodynamic consistency and formulation in terms of the principle of least action

• Published in: Chemical physics letters Vol. 723; pp. 118 - 122
• Main Author: Nath, Sunil
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 16.05.2019
• Subjects: Adenosine triphosphate; Average unit action; Complex systems; Efficiency; F1FO-ATP synthase; Molecular motors; Nath’s torsional mechanism of energy transduction and ATP synthesis; Nath’s two-ion theory of biological energy coupling; Nonequilibrium thermodynamics; Optimization; Oxidative phosphorylation; Selection of distance from equilibrium; Succinate anions; Total action; Variational principle; Selection of distance from equilibrium; Nath’s two-ion theory of biological energy coupling; Molecular motors; Average unit action; F1FO-ATP synthase; Total action; Complex systems; Optimization; Succinate anions; Oxidative phosphorylation; Efficiency; Variational principle; Nonequilibrium thermodynamics; Nath’s torsional mechanism of energy transduction and ATP synthesis; Adenosine triphosphate
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2019.03.029

[Display omitted] •The coupled processes of ATP synthesis operate at optimal thermodynamic efficiency.•The state is compatible with maximum dissipation under the imposed constraints.•These results are consistent with nonequilibrium thermodynamics.•The total action for a selected final state is a maximum compatible with the constraints.•The system evolves to a minimum unit action of 1.4 × 10−3 J s natom O−1 mg protein−1. The coupled nonequilibrium processes of ATP synthesis in oxidative phosphorylation (OX PHOS) are tuned such that the system operates at optimal thermodynamic efficiency, η. This state is compatible with maximum free energy dissipation, Φ under the imposed constraints. These results are shown to be consistent with nonequilibrium thermodynamics. Analysis of experimental data on rat liver mitochondria with succinate as substrate demonstrates that the total action of the system for a selected final state is a maximum compatible with the constraints, and that the system evolves with time to a minimum average unit action of 1.4 × 10−3 J s natom O−1 mg protein−1. This value of least average unit action corresponds to the highest efficiency of the system, compatible with the constraints to which the system is subject.