Boned Ricard, van Gunsteren Wilfred F, Daura Xavier
Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
Chemistry. 2008;14(16):5039-46. doi: 10.1002/chem.200701380.
The temperature dependence of thermodynamic quantities, such as heat capacity, entropy and free enthalpy, may be obtained by using well-known equations that relate these quantities to the enthalpy of the molecular system of interest at a range of temperatures. In turn, the enthalpy of a molecular system can be estimated from molecular dynamics simulations of an appropriate model. To demonstrate this, we have investigated the temperature dependence of the enthalpy, heat capacity, entropy and free enthalpy of a system that consists of a beta-heptapeptide in methanol and have used the statistical mechanics relationships to describe the thermodynamics of the folding/unfolding equilibrium of the peptide. The results illustrate the power of current molecular simulation force fields and techniques in establishing the link between thermodynamic quantities and conformational distributions.
诸如热容、熵和自由焓等热力学量的温度依赖性，可以通过使用一些知名方程来获得，这些方程将这些量与一系列温度下感兴趣的分子系统的焓联系起来。反过来，分子系统的焓可以从适当模型的分子动力学模拟中估算出来。为了证明这一点，我们研究了一个由甲醇中的β - 七肽组成的系统的焓、热容、熵和自由焓的温度依赖性，并使用统计力学关系来描述该肽折叠/去折叠平衡的热力学。结果说明了当前分子模拟力场和技术在建立热力学量与构象分布之间联系方面的能力。
