Molecular mechanics force-field development for amino acid zwitterions.
Molecular mechanics force-field development for amino acid zwitterions.
复制标题
氨基酸两性离子的分子力学力场开发。
DOI：
10.1002/jcc.10174
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Bowen,JP
中科院分区：
文献类型：
--
作者：
Kirschner,KN;Lewin,AH;Bowen,JP
Understanding the conformational flexibility of amino acid zwitterions (ZWs) and their associated conformational energies is crucial for predicting their interactions in biological systems. Gas‐phaseab initiocalculations of ZWs are intractable. Molecular mechanics (MM), on the other hand, is able to handle large systems but lacks the necessary force field parameters to model ZWs. To develop force field parameters that are able to correctly model ZW geometries and energetics we used a novel combinatorial approach: amino acid ZWs were broken down structurally into key functional components, which were parameterized separately. Møller–Plesset second‐order perturbation calculations on small carboxylates, on the glycine cation, and on novel hydrogen bonded systems, coupled with available experimental data, were used to generate MM3(2000) ZW parameters (Allinger N. L.; Yuh, Y. H.; Lii, J.‐H. J Am Chem Soc 1989, 111, 8551). The MM3 results from this combinatorial approach gave geometries that are in good agreement with neutron diffraction experiments, plus their frequencies and energies appear to be reasonably modeled. Current limitations and future development of MM force fields are discussed briefly. © 2002 Wiley Periodicals, Inc. J Comput Chem 24: 111–128, 2003
