General consideration of energy transduction by the ATPase-ATP system

Abstract

Abstract:The current dogma describes that the amount of biological work done by ATPase is limited only by the free energy change in the hydrolysis of ATP. However, this is not a principal requirement. As the system consists of both ATP and ATPase, it is the potential energy change in the entire system before and after ATP hydrolysis that should be considered. In this paper we reconsider the conceptual framework for energy transduction by the ATPase-ATP system from the point of view of the change in internal potential energy in the entire system.

The Complex Roles of Adenosine Triphosphate in Bioenergetics

“…Along the same lines, when considering the ATPase‐ATP system, Fukushima and Ushimaru have underscored the need to take into account the potential energy of the entire system before and after ATP hydrolysis [63] . Jencks has provided a detailed analysis of biological work in the cases of muscle contraction and active transport against a gradient of chemical potential, which include binding energy and a coupling process [50] .…”

“…[62] Along the same lines, when considering the ATPase-ATP system, Fukushima and Ushimaru have underscored the need to take into account the potential energy of the entire system before and after ATP hydrolysis. [63] Jencks has provided a detailed analysis of biological work in the cases of muscle contraction and active transport against a gradient of chemical potential, which include binding energy and a coupling process. [50] The modulation of binding energy is used to avoid both high-and low-energy intermediates that would respectively introduce a barrier to rapid turnover, or cause the enzyme to fall into an energy well.…”

The Inherent Energy in SR Ca2+‐ATPase Is Convertible into Chemical Work

“…For the ATP‐ATPase system, the current principle of bioenergetics holds that the energy that can be converted into work by ATPase derives only from ATP and that the ATPase molecule is merely a device of energy conversion. However, is there any energy available for work in the ATPase molecule?1 To answer this question, we have examined whether energy within the sarcoplasmic reticulum (SR) Ca 2+ ‐ATPase molecule can be converted into chemical work during synthesis of the high‐energy compound, ATP, from the low‐energy compound, p ‐nitrophenylphosphate (pNPP): …”