Dudich I V, Zav'ialov V P, Bumialis V A, Paulauskas D V
Mol Biol (Mosk). 1992 Mar-Apr;26(2):441-51.
Recombinant human gamma-interferon is dimeric in solution at pH 7-4 as revealed by analytical gel-filtration. It was shown by circular dichroism that decreasing pH to 5.0 does not affect the secondary and tertiary structures of gamma-interferon macromolecule. It was established that heat denaturation process of gamma-interferon obeys the two-state transition model and can be described as the first-order reversible reaction. Temperature dependence of the denaturation-renaturation rate constants was shown to be consistent with the Arrhenius law. The equilibrium value of the denaturation temperature was found. Effective enthalpy of denaturation was determined both by thermodynamic and kinetic approaches. The data obtained showed that in the pH range 7-4 the dimeric IFN-gamma structure may be considered as a single cooperative thermodynamic domain. Thus, it may be concluded that gamma-interferon dimerization is necessary for the existence of the corresponding tertiary structure of the macromolecule.
分析凝胶过滤显示，重组人γ干扰素在pH 7至4的溶液中呈二聚体形式。圆二色性表明，将pH降至5.0不会影响γ干扰素大分子的二级和三级结构。已确定γ干扰素的热变性过程遵循两态转变模型，可描述为一级可逆反应。变性-复性速率常数的温度依赖性与阿伦尼乌斯定律一致。找到了变性温度的平衡值。通过热力学和动力学方法测定了变性的有效焓。所获得的数据表明，在pH 7至4的范围内，二聚体IFN-γ结构可被视为一个单一的协同热力学结构域。因此，可以得出结论，γ干扰素二聚化对于大分子相应三级结构的存在是必要的。
