Département de Chimie, Laboratoire des Mécanismes Réactionnels, Ecole Polytechnique, 91120 Palaiseau, France.
Mass Spectrom Rev. 2012 May-Jun;31(3):391-435. doi: 10.1002/mas.20349.
The present article is the third part of a general overview of the gas-phase protonation thermochemistry of polyfunctional molecules (first part: Mass Spectrom. Rev., 2007, 26:775-835, second part: Mass Spectrom. Rev., 2011, in press). This review is devoted to the 20 proteinogenic amino acids and is divided in two parts. In the first one, the experimental data obtained during the last 30 years using the equilibrium, thermokinetic and kinetic methods are presented. A general re-assignment of the values originating from these various experiments has been done on the basis of the commonly accepted Hunter & Lias 1998 gas-phase basicity scale in order to provide an homogeneous set of data. In the second part, theoretical investigations on gaseous neutral and protonated amino acids are reviewed. Conformational landscapes of both types of species were examined in order to provide theoretical protonation thermochemistry based on the truly identified most stable conformers. Proton affinities computed at the presently highest levels of theory (i.e. composite methods such as Gn procedures) are presented. Estimates of thermochemical parameters calculated using a Boltzmann distribution of conformers at 298K are also included. Finally, comparison between experiment and theory is discussed and a set of evaluated proton affinities, gas-phase basicities and protonation entropies is proposed.
本文是多官能团分子气相质子化热化学综述的第三部分（第一部分：质谱评论，2007，26：775-835；第二部分：质谱评论，2011，即将出版）。该综述专注于 20 种蛋白氨基酸，并分为两部分。在第一部分中，展示了过去 30 年使用平衡、热动力学和动力学方法获得的实验数据。基于普遍接受的 Hunter 和 Lias 1998 气相碱度标度，对这些各种实验产生的值进行了重新赋值，以便提供一组同质数据。在第二部分中，综述了气态中性和质子化氨基酸的理论研究。为了基于真正确定的最稳定构象提供理论质子化热化学，检查了这两种类型的物种的构象景观。呈现了在目前最高理论水平（即 Gn 程序等复合方法）上计算的质子亲和能。还包括使用 298K 构象的玻尔兹曼分布计算的热化学参数的估计值。最后，讨论了实验和理论之间的比较，并提出了一组评估的质子亲和能、气相碱度和质子化熵。
