Title
Molecular mechanics force-field development for amino acid zwitterions.
Abstract
Understanding the conformational flexibility of amino acid zwitterions (ZWs) and their associated conformational energies is crucial for predicting their interactions in biological systems. Gas-phase ab initio calculations 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. Moller-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. I Am Chem See 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. (C) 2002 Wiley Periodicals, Inc.
Year
DOI
Venue
2003
10.1002/jcc.10174
JOURNAL OF COMPUTATIONAL CHEMISTRY
Keywords
Field
DocType
amino acid zwitterion,molecular mechanics,drug development,combinatorial parameterization,carboxylate
Molecular mechanics,Force field (physics),Neutron diffraction,Ab initio quantum chemistry methods,Amino acid,Computational chemistry,Chemistry
Journal
Volume
Issue
ISSN
24
1
0192-8651
Citations 
PageRank 
References 
1
0.43
1
Authors
3
Name
Order
Citations
PageRank
Karl Nicholas Kirschner110.43
Anita H. Lewin231.54
J. Phillip Bowen31513.55