Chun Paul W
Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida 32610-0245, USA.
Biophys J. 2003 Feb;84(2 Pt 1):1352-69. doi: 10.1016/S0006-3495(03)74951-0.
Applying the Planck-Benzinger methodology, the sequence-specific hydrophobic interactions of 35 dipeptide pairs were examined over a temperature range of 273-333 K, based on data reported by Nemethy and Scheraga in 1962. The hydrophobic interaction in these sequence-specific dipeptide pairs is highly similar in its thermodynamic behavior to that of other biological systems. The results imply that the negative Gibbs free energy change minimum at a well-defined stable temperature, <T(s)>, where the bound unavailable energy, TdeltaS(o) = 0, has its origin in the sequence-specific hydrophobic interactions, are highly dependent on details of molecular structure. Each case confirms the existence of a thermodynamic molecular switch wherein a change of sign in deltaCp(o)(T)(reaction) (change in specific heat capacity of reaction at constant pressure) leads to true negative minimum in the Gibbs free energy change of reaction, deltaG(o)(T)(reaction), and hence a maximum in the related equilibrium constant, K(eq). Indeed, all interacting biological systems examined to date by Chun using the Planck-Benzinger methodology have shown such a thermodynamic switch at the molecular level, suggesting its existence may be universal.
基于内梅蒂和舍拉加在1962年报告的数据，运用普朗克 - 本津格方法，在273 - 333 K的温度范围内研究了35对二肽的序列特异性疏水相互作用。这些序列特异性二肽对中的疏水相互作用在热力学行为上与其他生物系统的高度相似。结果表明，在明确的稳定温度<T(s)>下吉布斯自由能变化最小值为负，此时结合的不可用能量TΔS(o) = 0，其源于序列特异性疏水相互作用，高度依赖于分子结构细节。每个案例都证实了存在一种热力学分子开关，其中δCp(o)(T)(反应)（恒压下反应的比热容变化）符号的改变导致反应吉布斯自由能变化δG(o)(T)(反应)出现真正的负最小值，从而使相关平衡常数K(eq)达到最大值。事实上，春使用普朗克 - 本津格方法迄今研究的所有相互作用生物系统在分子水平上都显示出这样一种热力学开关，表明其存在可能具有普遍性。
