Institut für Chemie und Biochemie, Freie Universität Berlin, Forschungsbau SupraFab, Altensteinstrasse 23a, 14195 Berlin, Germany.
Biomolecules. 2024 Nov 8;14(11):1421. doi: 10.3390/biom14111421.
A thermodynamic analysis of the binary complex formation of the highly positively charged linker histone H1 and the highly negatively charged chaperone prothymosin α (ProTα) is detailed. ProTα and H1 have large opposite net charges (-44 and +53, respectively) and form complexes at physiological salt concentrations with high affinities. The data obtained for the binary complex formation are analyzed by a thermodynamic model that is based on counterion condensation modulated by hydration effects. The analysis demonstrates that the release of the counterions mainly bound to ProTα is the main driving force, and effects related to water release play no role within the limits of error. A strongly negative Δ (=-0.87 kJ/(K mol)) is found, which is due to the loss of conformational degrees of freedom.
详细介绍了带正电荷的连接组蛋白 H1 和带负电荷的伴侣蛋白 prothymosin α (ProTα) 之间的二元复合物形成的热力学分析。ProTα 和 H1 的净电荷分别为-44 和+53，具有很大的相反净电荷，并在生理盐浓度下以高亲和力形成复合物。通过基于水合作用调节抗衡离子凝聚的热力学模型分析二元复合物形成的数据。分析表明，主要与 ProTα 结合的抗衡离子的释放是主要驱动力，在误差范围内，与水释放相关的效应不起作用。发现强烈的负 Δ（=-0.87 kJ/（K mol）），这是由于构象自由度的丧失。
