Prediction of binding affinities for TIBO inhibitors of HIV-1 reverse transcriptase using Monte Carlo simulations in a linear response method
| Autor: | William L. Jorgensen, Paul A. J. Janssen, Richard H. Smith, Julian Tirado-Rives, Marilyn B. Kroeger Smith, Christopher J. Michejda, Michelle Lamb |
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| Rok vydání: | 1998 |
| Předmět: |
Models
Molecular Molecular model Stereochemistry Anti-HIV Agents Monte Carlo method Molecular Conformation Protonation Accessible surface area symbols.namesake Benzodiazepines Computational chemistry Sasa Drug Discovery Root-mean-square deviation Binding Sites biology Chemistry Hydrogen bond Imidazoles Hydrogen Bonding biology.organism_classification HIV Reverse Transcriptase symbols Molecular Medicine Reverse Transcriptase Inhibitors van der Waals force Monte Carlo Method |
| Zdroj: | Journal of medicinal chemistry. 41(26) |
| ISSN: | 0022-2623 |
| Popis: | Monte Carlo (MC) simulations in combination with a linear response approach were used to estimate the free energies of binding for a series of 12 TIBO nonnucleoside inhibitors of HIV-1 reverse transcriptase. Separate correlations were made for the R6 and S6 absolute conformations of the inhibitors, as well as for the analogous N6-monoprotonated species. Models based upon the neutral unbound inhibitors produced overall better fits to experimental values than did those using the protonated unbound inhibitors, with only slight differences between the neutral R6 and S6 cases. The best results were obtained with a three-parameter linear response equation containing van der Waals (alpha), electrostatic (beta), and solvent accessible surface area (SASA, gamma) terms. The averaged (R6 and S6) rms error was approximately 0.88 kcal/mol for the observed range of 4.06 kcal/mol in inhibitor activities. The averaged values of alpha, beta, and gamma were -0.150, 0.114, and 0. 0286, respectively. Omission of the alpha term gave beta 0.152 and gamma 0.022 with a rms of 0.92. The unweighted van der Waals components were found to be highly attractive but failed to correlate well across the series of inhibitors. Contrastingly, while the electrostatic components are all repulsive, they show a direct correlation with inhibitor activity as measured by DeltaGbinding. The role of gamma is primarily to produce an overall negative binding energy, and it can effectively be replaced with a negative constant. During the MC simulations of the unbound solvated inhibitors, the R6 and S6 absolute conformations do not interconvert due to the formation of a favorable hydrogen bond to solvent. In the complex, however, interconversion of these conformations of the inhibitor is observed during the course of the simulations, a phenomenon which is apparently not observed in the crystalline state of the complex. Hydrogen bonding of the inhibitor to the backbone NH of K101 and the lack of such an interaction with the C=O of K101 or with solvent correlate with enhanced activity, as does the ability to assume a number of different orientations of the inhibitor dimethylallyl moiety with respect to residues Y181 and Y188 while retaining contact with W229. Overall, the use of a combination of MC simulation with a linear response method shows promise as a relatively rapid means of estimating inhibitor activities. This approach should be useful in the preliminary evaluation of potential modifications to known inhibitors to enhance activity. |
| Databáze: | OpenAIRE |
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