Mosavi-Movahedi A A, Jones M M, Pilcher G
Department of Biochemistry and Molecular Biology, University of Manchester, UK.
Int J Biol Macromol. 1989 Feb;11(1):26-8. doi: 10.1016/0141-8130(89)90035-4.
The thermodynamic parameters for the interaction between sodium n-dodecyl sulphate (SDS) and Aspergillus niger catalase in aqueous solution at pH 3.2 and 6.4 have been measured by microcalorimetry and equilibrium dialysis over a range of ionic strength from 0.05 to 0.2 at 25 degrees C. Binding isotherms have been interpreted in terms of theoretical models (Hill equation and Wyman binding potential). The Gibbs energies of interaction become increasingly negative with increase in ionic strength and the entropies of interaction become increasingly positive. The ionic strength dependence of the Gibbs energies are much greater than predicted by the Debye-Hückel limiting law indicating a strongly ionic strength dependent hydrophobic contribution to the interactions.
在25摄氏度下，通过微量量热法和平衡透析法，在pH值为3.2和6.4的水溶液中，于0.05至0.2的离子强度范围内，测定了正十二烷基硫酸钠（SDS）与黑曲霉过氧化氢酶相互作用的热力学参数。结合等温线已根据理论模型（希尔方程和怀曼结合势）进行了解释。随着离子强度的增加，相互作用的吉布斯自由能变得越来越负，而相互作用的熵则变得越来越正。吉布斯自由能对离子强度的依赖性远大于德拜-休克尔极限定律的预测，这表明相互作用中存在强烈依赖离子强度的疏水贡献。
