Enzyme cascade to enzyme complex phase-transition-like transformation studied by the maximum entropy production principle

In biological cells, soluble enzymes often spontaneously reorganize into higher-order complexes called metabolons, providing regulatory advantages over individual soluble enzymes under specific conditions. Despite their importance, the mechanisms underlying metabolon formation remain unclear. Here we report a theoretical model that elucidates the spontaneous transition between soluble enzyme cascades and complexes, driven by fluctuations in intermediate metabolite concentrations. The model integrates the maximum entropy production principle (MEPP) and the Shannon information entropy (MaxEnt), Landau phase-transition theory, kinetic modeling, stability analysis, and metabolic control analysis. Our results show that soluble enzymes and enzyme complexes represent two distinct catalytic states with unique kinetic and regulatory properties. The transition from an enzyme cascade to an enzyme complex displays features of a first-order phase transition, highlighting the system's tendency to reorganize into its most thermodynamically favorable state, providing a potential pathway for metabolic regulation.