Lantos Emese, Mótyán Gergő, Frank Éva, Eelkema Rienk, van Esch Jan, Horváth Dezső, Tóth Ágota
Department of Physical Chemistry and Materials Science, University of Szeged Rerrich Béla tér 1 Szeged H-6720 Hungary
Department of Organic Chemistry, University of Szeged Dóm tér 8. Szeged H-6720 Hungary.
RSC Adv. 2023 Jul 5;13(29):20243-20247. doi: 10.1039/d3ra04215d. eCollection 2023 Jun 29.
In living systems adaptive regulation requires the presence of nonlinear responses in the underlying chemical networks. Positive feedbacks, for example, can lead to autocatalytic bursts that provide switches between two stable states or to oscillatory dynamics. The stereostructure stabilized by hydrogen bonds provides an enzyme its selectivity, rendering pH regulation essential for its functioning. For effective control, triggers by small concentration changes play roles where the strength of feedback is important. Here we show that the interaction of acid-base equilibria with simple reactions with pH-dependent rate can lead to the emergence of a positive feedback in hydroxide ion concentration during the hydrolysis of some Schiff bases in the physiological pH range. The underlying reaction network can also support bistability in an open system.
在生命系统中，适应性调节需要基础化学网络中存在非线性响应。例如，正反馈可导致自催化爆发，从而在两个稳定状态之间提供切换或产生振荡动力学。由氢键稳定的立体结构赋予酶选择性，使得pH调节对其功能至关重要。对于有效的控制而言，在反馈强度很重要的情况下，由小浓度变化引发的触发作用就会发挥作用。在此我们表明，在生理pH范围内，酸碱平衡与具有pH依赖性速率的简单反应之间的相互作用，可导致某些席夫碱水解过程中氢氧根离子浓度出现正反馈。基础反应网络在开放系统中也可支持双稳态。
