Im Suk, Jang Sung-Woo, Lee Sungyul, Lee Yonghoon, Kim Bongsoo
College of Environmental Science and Applied Chemistry (BK21), Kyunghee University, Kyungki 449-701, S. Korea.
J Phys Chem A. 2008 Oct 9;112(40):9767-70. doi: 10.1021/jp801933y.
We present calculations for the Arg-H2O system and predict that the zwitterionic Arg is thermodynamically more stable than the canonical form in the gas phase under the influence of a single water molecule because of the strongly basic guanidine side chain. Canonical conformers of Arg-H2O are found to isomerize to the zwitterionic forms via a small barrier (approximately 6 kcal/mol).
我们给出了精氨酸-水体系的计算结果，并预测在单个水分子的影响下，由于胍基侧链的强碱性，两性离子形式的精氨酸在气相中比标准形式在热力学上更稳定。发现精氨酸-水的标准构象体通过一个小的势垒（约6千卡/摩尔）异构化为两性离子形式。
