Mass spectrometric and quantum-chemical study on the structure, stability, and chirality of protonated serine dimers.
Mass spectrometric and quantum-chemical study on the structure, stability, and chirality of protonated serine dimers.
复制标题
质子化丝氨酸二聚体的结构、稳定性和手性的质谱和量子化学研究。
DOI：
10.1002/chem.200401226
复制
发表时间：
2005
期刊：
影响因子：
--
通讯作者：
A. Császár
中科院分区：
文献类型：
--
作者：
Ferenc Pollreisz;Á. Gömöry;Gitta Schlosser;K. Vékey;I. Solt;A. Császár
通过结合质谱法和从头算量子化学计算，研究了同手性和异手性质子化丝氨酸 (Ser) 二聚体的稳定性和结构。这表明最稳定的同手性和异手性形式之间的能量差异非常小：串联质谱与库克斯动力学方法产生的吉布斯自由能差异可以忽略不计（0.2+/-0.2 kJ mol(-1)）。 (Ser)2 H+ 的各种异构形式及其能量通过广泛的电子结构计算确定，产生具有明显不同相对能量的异构体的同手性和异手性形式。最稳定的纯手性异构体由两个氢键稳定，并且比任何其他纯手性异构体稳定得多。最稳定的异手性异构体具有完全不同的特征，其特征是盐桥结构。这清楚地表明，即使在相对较小的分子中并且在不存在特别碱性或酸性官能团的情况下，盐桥结构也确实存在于气相中。
Stability and structure of homo- and heterochiral protonated serine (Ser) dimers were investigated by a combination of mass spectrometry and ab initio quantum chemical calculations. This established that the energy difference between the most stable homo- and heterochiral forms is very small: tandem mass spectrometry with Cooks' kinetic method yielded a negligible difference in Gibbs free energy (0.2+/-0.2 kJ mol(-1)). The various isomeric forms of (Ser)2 H+ and their energetics were determined by extensive electronic-structure calculations, which yielded homo- and heterochiral forms of the isomers with distinctly different relative energies. The most stable homochiral isomer is stabilized by two hydrogen bonds and is far more stable than any other homochiral isomer. The most stable heterochiral isomer has completely different features, and it is characterized by a salt-bridge structure. This clearly shows that salt-bridge structures do exist in the gas phase even in comparatively small molecules and in the absence of particularly basic or acidic functional groups.
影响因子：
2.9
作者：
Jockusch, RA;Price, WD;Williams, ER
通讯作者：
Williams, ER