The Influence of Crowding Conditions on the Thermodynamic Feasibility of Metabolic Pathways
The Influence of Crowding Conditions on the Thermodynamic Feasibility of Metabolic Pathways
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DOI：
10.1016/j.bpj.2015.09.030
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发表时间：
2015-12-01
影响因子：
3.4
通讯作者：
Theodoropoulos, Constantinos
中科院分区：
文献类型：
--
作者：
Angeles-Martinez, Liliana;Theodoropoulos, Constantinos
细胞内反应在拥挤的培养基中进行，其中大分子占据总体积的40%。可用体积的这种减少影响反应物的活性。比例粒子理论用于估计代谢物的活度系数，从而评估背景分子的存在对估计反应的吉布斯自由能变化（Δ（r）G）的影响。乳酸途径和中心碳代谢的琥珀酸放线杆菌从甘油生产琥珀酸已被用作说明性的案例研究。结果表明，维持细胞内拥挤区域的重要性，有利于在其他情况下不可行的途径的可行性。此外，拥挤条件可能会改变反应的方向性，并可以修改可行的范围内的通量估计的代谢系统相比，在标准的生物条件下获得的。
Intracellular reactions are carried out in a crowded medium where the macromolecules occupy similar to 40% of the total volume. This decrease in the available volume affects the activity of the reactants. Scaled particle theory is used for the estimation of the activity coefficients of the metabolites, and thereby for the assessment of the impact of the presence of background molecules, on the estimation of the Gibbs free energy change (Delta(r)G) of the reactions. The lactic acid pathway and the central carbon metabolism of Actinobacillus succinogenes for the production of succinic acid from glycerol have been used as illustrative case studies. Results suggest the importance of maintaining intracellular crowded regions to favor the feasibility of a pathway that in other circumstances would be infeasible. Moreover, the crowding conditions may change the directionality of reactions and can modify the feasible range of fluxes estimated for a metabolic system compared with those obtained at standard biological conditions.