Thermodynamic optimality of glycolytic oscillations

TL;DR

This paper investigates the thermodynamic efficiency of glycolytic oscillations, showing they are optimized for minimal entropy production at biologically relevant periods, aligning with thermodynamic uncertainty principles.

Contribution

It demonstrates that glycolytic oscillations operate near thermodynamic optimality, minimizing entropy production within physiological parameter ranges, and links oscillation stability to phase boundary proximity.

Findings

Glycolytic oscillations are most cost-effective at 5-10 minutes period.

Oscillations occur near the phase boundary of limit cycles.

Increased glucose disrupts oscillatory dynamics.

Abstract

Temporal order in living matters reflects the self-organizing nature of dynamical processes driven out of thermodynamic equilibrium. Because of functional reason, the period of a biochemical oscillation must be tuned to a specific value with precision; however, according to the thermodynamic uncertainty relation (TUR), the precision of oscillatory period is constrained by the thermodynamic cost of generating it. After reviewing the basics of chemical oscillations using Brusselator as a model system, we study the glycolytic oscillation generated by octameric phosphofructokinase (PFK), which is known to display a period of several minutes. By exploring the phase space of glycolytic oscillations, we find that the glycolytic oscillation under the cellular condition is realized in a cost effective manner. Specifically, over the biologically relevant range of parameter values of glycolysis and octameric PFK, the entropy production from the glycolytic oscillation is minimal when the oscillation period is (5 - 10) minutes. Further, the glycolytic oscillation is found at work near the phase boundary of limit cycles, suggesting that a moderate increase of glucose injection rate leads to the loss of oscillatory dynamics, which is reminiscent of the loss of pulsatile insulin release resulting from elevated blood glucose level.