Hiebl M, Maksymiw R
Technische Universität München, Physik Department, Garching, Germany.
Biopolymers. 1991 Feb 5;31(2):161-7. doi: 10.1002/bip.360310204.
The temperature dependence of the apparent expansibility of lysozyme and ovalbumin in solution has been measured as a function of pH. This temperature dependence is explained in terms of suppressed fluctuations in bound water due to the protein. It is shown that the thermal expansion coefficient of bound water is different from bulk water. The pH dependence can be explained by increased hydration of side chains at lower pH. The amount in volume of hydration water in a typical protein-water system varies from 0.16 to 0.7. How the intrinsic thermal expansion coefficient of proteins can be derived from the apparent quantity is discussed. Intrinsic values of the thermal expansion coefficient for lysozyme at room temperature are between 1.7 and 4.4 x 10(-4) K-1 for a 10% solution.
已测量了溶菌酶和卵清蛋白在溶液中的表观膨胀系数随温度的变化，并将其作为pH值的函数。这种温度依赖性可以用蛋白质对结合水波动的抑制来解释。结果表明，结合水的热膨胀系数与体相水不同。pH依赖性可以通过较低pH值下侧链水合作用的增加来解释。在典型的蛋白质-水体系中，水合水的体积量在0.16至0.7之间变化。本文讨论了如何从表观量推导出蛋白质的固有热膨胀系数。对于10%的溶液，室温下溶菌酶热膨胀系数的固有值在1.7至4.4×10⁻⁴K⁻¹之间。
