A simple method for calculating atomic charges in charged molecular systems of biochemical interest

✍ Scribed by John Mullay

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 722 KB
• Volume: 12
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.540120310

✦ Synopsis

A previously developed method for calculating atomic charge in neutral molecules is modified so as to account for charged molecular species. The method is based on the orbital electronegativity (EN) concept and utilizes an EN equalization principal. Since only one linear equation is required per bond in the molecule, the scheme is extremely simple to use and thus is readily applicable to larger molecules of interest to biochemistry. Atom charge results are compared to ab initio calculations as well as experimental data from NMR and X-ray diffraction studies. It is shown that the method compares very well even with higher level theoretical methods for a variety of charged molecules including alanine and protonated adenine. It is also shown that NMR chemical shift data for charged amino acids are correlated quite well with atomic charges from the present method. In addition charges obtained from X-ray diffraction data for both ionic alanine and 2'-deoxycytidine-5'-monophosphate are also reproduced very well.