Title
Computational alanine scanning mutagenesis - An improved methodological approach.
Abstract
Alanine scanning mutagenesis of protein-protein interfacial residues can be applied to a wide variety of protein complexes to understand the structural and energetic characteristics of the hot-spots. Binding free energies have been estimated with reasonable accuracy with empirical methods, such as Molecular Mechanics/Poisson-Boltzmann surface area (MM-PBSA), and with more rigorous computational approaches like Free Energy Perturbation (FEP) and Thermodynamic Integration (TI). The main objective of this work is the development of an improved methodological approach, with less computational cost, that predicts accurately differences in binding free energies between the wild-type and alanine mutated complexes (Delta Delta G(binding)). The method was applied to three complexes, and a mean unsigned error of 0.80 kcal/mol was obtained in a set of 46 mutations. The computational method presented here achieved an overall success rate of 80% and an 82% success rate in residues for which alanine mutation causes an increase in the binding free energy > 2.0 kcal/mol (warm- and hot-spots). This fully atomistic computational methodological approach consists in a computational Molecular Dynamics simulation protocol performed in a continuum medium using the Generalized Born model. A set of three different internal dielectric constants, to mimic the different degree of relaxation of the interface when different types of amino acids are mutated for alanine, have to be used for the proteins, depending on the type of amino acid that is mutated. This method permits a systematic scanning mutagenesis of protein-protein interfaces and it is capable of anticipating the experimental results of mutagenesis, thus guiding new experimental investigations. (C) 2006 Wiley Periodicals, Inc.
Year
DOI
Venue
2007
10.1002/jcc.20566
JOURNAL OF COMPUTATIONAL CHEMISTRY
Keywords
Field
DocType
alanine scanning mutagenesis,computational mutagenesis,MM-PBSA,hot-spot,binding free energy,protein-protein interfaces,molecular mechanics,Poisson-Boltzmann,Generalized Born model
Poisson–Boltzmann equation,Alanine scanning,Alanine,Amino acid,Computational chemistry,Chemistry,Molecular dynamics,Mutagenesis,Free energy perturbation,Thermodynamic integration
Journal
Volume
Issue
ISSN
28
3
0192-8651
Citations 
PageRank 
References 
20
1.29
6
Authors
3
Name
Order
Citations
PageRank
Irina S. Moreira1384.98
Pedro Alexandrino Fernandes2477.17
Maria João Ramos3529.63