1. Enzyme cascade to enzyme complex phase-transition-like transformation studied by the maximum entropy production principleAndrej Dobovišek, Tina Blaževič, Samo Kralj, Aleš Fajmut, 2025, izvirni znanstveni članek Opis: 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 phasetransition, highlighting the system's tendency to reorganize into its most thermodynamically favorable state, providing a potential pathway for metabolic regulation.
Ključne besede: theoretical modeling, irreversible thermodynamics, maximum entropy production principle, Shannon information entropy, first-order phase transition, enzyme organization, enzyme cascade, enzyme complex
Objavljeno v DKUM: 06.02.2025; Ogledov: 0; Prenosov: 1
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2. Self-organization of enzyme-catalyzed reactions studied by the maximum entropy production principleAndrej Dobovišek, Marko Vitas, Tina Blaževič, Rene Markovič, Marko Marhl, Aleš Fajmut, 2023, izvirni znanstveni članek Opis: The self-organization of open reaction systems is closely related to specific mechanisms that allow the export of internally generated entropy from systems to their environment. According to the second law of thermodynamics, systems with effective entropy export to the environment are better internally organized. Therefore, they are in thermodynamic states with low entropy. In this context, we study how self-organization in enzymatic reactions depends on their kinetic reaction mechanisms. Enzymatic reactions in an open system are considered to operate in a non-equilibrium steady state, which is achieved by satisfying the principle of maximum entropy production (MEPP). The latter is a general theoretical framework for our theoretical analysis. Detailed theoretical studies and comparisons of the linear irreversible kinetic schemes of an enzyme reaction in two and three states are performed. In both cases, in the optimal and statistically most probable thermodynamic steady state, a diffusion-limited flux is predicted by MEPP. Several thermodynamic quantities and enzymatic kinetic parameters, such as the entropy production rate, the Shannon information entropy, reaction stability, sensitivity, and specificity constants, are predicted. Our results show that the optimal enzyme performance may strongly depend on the number of reaction steps when linear reaction mechanisms are considered. Simple reaction mechanisms with a smaller number of intermediate reaction steps could be better organized internally and could allow fast and stable catalysis. These could be features of the evolutionary mechanisms of highly specialized enzymes.
Ključne besede: enzymes, kinetic data analysis, steady state, self-organization, maximum entropy production
Objavljeno v DKUM: 08.05.2024; Ogledov: 234; Prenosov: 11
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3. The maximum entropy production principle and linear irreversible processesPaško Županović, Domagoj Kuić, Željana Bonačić Lošić, Dražen Petrov, Davor Juretić, Milan Brumen, 2010, izvirni znanstveni članek Opis: It is shown that Onsager’s principle of the least dissipation of energy is equivalent to the maximum entropy production principle. It is known that solutions of the linearized Boltzmann equation make extrema of entropy production. It is argued, in the case of stationary processes, that this extremum is a maximum rather than a minimum.
Ključne besede: entropy production, linear nonequilibrium thermodynamics, linearized Boltzmann equation
Objavljeno v DKUM: 21.06.2017; Ogledov: 1249; Prenosov: 407
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4. On the problem of formulating principles in nonequilibrium thermodynamicsPaško Županović, Domagoj Kuić, Davor Juretić, Andrej Dobovišek, 2010, izvirni znanstveni članek Opis: In this work, we consider the choice of a system suitable for the formulation of principles in nonequilibrium thermodynamics. It is argued that an isolated system is a much better candidate than a system in contact with a bath. In other words, relaxation processes rather than stationary processes are more appropriate for the formulation of principles in nonequilibrium thermodynamics. Arguing that slow varying relaxation can be described with quasi-stationary process, it is shown for two special cases, linear nonequilibrium thermodynamics and linearized Boltzmann equation, that solutions of these problems are in accordance with the maximum entropy production principle.
Ključne besede: thermodynamics, entropy, relaxation, stationary process, entropy production
Objavljeno v DKUM: 07.06.2012; Ogledov: 1627; Prenosov: 401
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