Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, USA.
J Am Soc Mass Spectrom. 2009 Nov;20(11):2116-23. doi: 10.1016/j.jasms.2009.07.006. Epub 2009 Jul 14.
The proton affinities of the 20 common amino acids have been computed at the G3MP2 level using structures derived from broad conformational searches at a variety of levels including G3MP2. In some cases, the conformational surveys identified more stable species than had been used in previous studies of proton affinities, though the differences in energy are sometimes rather small. The present values are likely the most reliable measure of amino acid proton affinities in the gas phase. An analysis of differences between these values and those obtained experimentally via the kinetic method indicates that the extraction of proton affinities from kinetic method data can potentially lead to large errors linked to the estimation of relative protonation entropies.
使用源自广泛构象搜索的结构，在包括 G3MP2 在内的多种水平上，计算了 20 种常见氨基酸的质子亲和力。在某些情况下，构象调查确定了比以前研究质子亲和力时使用的更稳定的物种，尽管能量差异有时很小。目前的值可能是气相中氨基酸质子亲和力最可靠的测量值。对这些值与通过动力学方法实验获得的值之间的差异的分析表明，从动力学方法数据中提取质子亲和力可能会导致与相对质子化熵估计相关的大误差。
