The broad goals of this project are the development of novel theoretical models and practical computational tools that will improve and facilitate the process of modeling and simulating bio-molecules. The new models will be based on """"""""implicit solvent"""""""" approach in which individual water molecules and mobile solvent ions are replaced by a continuous medium with the average properties of the solvent. Currently, the """"""""engine"""""""" of the methodology - responsible for the estimation of the key electrostatic interactions - is either the generalized Born (GB) or the Poisson Boltzmann model (PB). The GB model is computationally efficient, but lacks the critical accuracy of the fundamental, but computationally expensive PB approach. Within the proposed approach, exact solutions of the PB equation for typical molecular shapes will serve as the foundation for deriving computationally efficient, analytical models. The models will go beyond the current generation of the generalized Born (GB) models, in both accuracy and efficiency. New important features will be added, such as the ability to compute electrostatic potential at every point in space: potential generated by a bio-molecule is often a key determinant of its function. For large compounds, e.g. multi-protein complexes, viral capsids, the ribosome or the nucleosome, the proposed approach may be the only practical way to generate potential maps with the power of a desktop computer. Approaches specifically targeted to speed-up simulations based on the implicit solvent models will be developed. They will be based upon coarse-graining of the charge distribution and will not have the significant artifacts typical of the """"""""standard"""""""" schemes in which interactions beyond a specified distance are neglected. The methods will yield at least a 10-fold increase in computational speed for large bio-molecular structures. The use of the new models will be expanded to applications where the GB model is currently not applied, but where computational speed and accuracy are critical, for example in quantum mechanics-molecular mechanics (QM-MM) calculations on bio-molecules. The fast, analytical models of solvation will become more dependable. The models will be used to gain insights into the molecular mechanism of enhanced flexibility of short DNA fragments.

Public Health Relevance

Molecular modeling and simulations are nowadays indispensable tools in biomedical science and the drug discovery process. The proposed methods will significantly enhance their accuracy and speed. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
1R01GM076121-01A1
Application #
7142905
Study Section
Special Emphasis Panel (ZRG1-BCMB-Q (02))
Program Officer
Lyster, Peter
Project Start
2006-08-01
Project End
2011-07-31
Budget Start
2006-08-01
Budget End
2007-07-31
Support Year
1
Fiscal Year
2006
Total Cost
$218,837
Indirect Cost
Name
Virginia Polytechnic Institute and State University
Department
Biostatistics & Other Math Sci
Type
Schools of Engineering
DUNS #
003137015
City
Blacksburg
State
VA
Country
United States
Zip Code
24061
Katkova, E V; Onufriev, A V; Aguilar, B et al. (2017) Accuracy comparison of several common implicit solvent models and their implementations in the context of protein-ligand binding. J Mol Graph Model 72:70-80
Izadi, Saeed; Onufriev, Alexey V (2016) Accuracy limit of rigid 3-point water models. J Chem Phys 145:074501
Izadi, Saeed; Anandakrishnan, Ramu; Onufriev, Alexey V (2016) Implicit Solvent Model for Million-Atom Atomistic Simulations: Insights into the Organization of 30-nm Chromatin Fiber. J Chem Theory Comput 12:5946-5959
Izadi, Saeed; Aguilar, Boris; Onufriev, Alexey V (2015) Protein-Ligand Electrostatic Binding Free Energies from Explicit and Implicit Solvation. J Chem Theory Comput 11:4450-9
Mukhopadhyay, Abhishek; Tolokh, Igor S; Onufriev, Alexey V (2015) Accurate evaluation of charge asymmetry in aqueous solvation. J Phys Chem B 119:6092-100
Anandakrishnan, Ramu; Drozdetski, Aleksander; Walker, Ross C et al. (2015) Speed of conformational change: comparing explicit and implicit solvent molecular dynamics simulations. Biophys J 108:1153-64
Mukhopadhyay, Abhishek; Aguilar, Boris H; Tolokh, Igor S et al. (2014) Introducing Charge Hydration Asymmetry into the Generalized Born Model. J Chem Theory Comput 10:1788-1794
Onufriev, Alexey V; Aguilar, Boris (2014) Accuracy of continuum electrostatic calculations based on three common dielectric boundary definitions. J Theor Comput Chem 13:
Anandakrishnan, Ramu; Baker, Charles; Izadi, Saeed et al. (2013) Point charges optimally placed to represent the multipole expansion of charge distributions. PLoS One 8:e67715
Onufriev, Alexey V; Alexov, Emil (2013) Protonation and pK changes in protein-ligand binding. Q Rev Biophys 46:181-209

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