A Protocol to Use Comparative Binding Energy Analysis to Estimate Drug-Target Residence Time.

Comparative Binding Energy (COMBINE) analysis is an approach for deriving a target-specific scoring function to compute binding free energy, drug-binding kinetics, or a related property by exploiting the information contained in the three-dimensional structures of receptor-ligand complexes. Here, we describe the process of setting up and running COMBINE analysis to derive a Quantitative Structure-Kinetics Relationship (QSKR) for the dissociation rate constants (k) of inhibitors of a drug target. The derived QSKR model can be used to estimate residence times (τ, τ=1/k) for similar inhibitors binding to the same target, and it can also help to identify key receptor-ligand interactions that distinguish inhibitors with short and long residence times.

KBbox: A Toolbox of Computational Methods for Studying the Kinetics of Molecular Binding.

The past few years have seen increasing recognition of the importance of understanding molecular binding kinetics. This has led to the development of myriad computational methods for studying the kinetics of binding processes and predicting their associated rate constants that show varying ranges of application, degrees of accuracy, and computational requirements. In order to help researchers decide which method might be suitable for their projects, we have developed KBbox, a web server that guides users in choosing the methods they should consider on the basis of the information they wish to obtain, the data they currently have available, and the computational resources to which they have access.

Prediction of Drug-Target Binding Kinetics by Comparative Binding Energy Analysis.

A growing consensus is emerging that optimizing the drug-target affinity alone under equilibrium conditions does not necessarily translate into higher potency in vivo and that instead binding kinetic parameters should be optimized to ensure better efficacy. Therefore, in silico methods are needed to predict the kinetic parameters and the mechanistic determinants of drug-protein binding. Here we demonstrate the application of COMparative BINding Energy (COMBINE) analysis to derive quantitative structure-kinetics relationships (QSKRs) for the dissociation rate constants ( ) of inhibitors of heat shock protein 90 (HSP90) and HIV-1 protease.

Halogen-Aromatic π Interactions Modulate Inhibitor Residence Times.

Prolonged drug residence times may result in longer-lasting drug efficacy, improved pharmacodynamic properties, and "kinetic selectivity" over off-targets with high drug dissociation rates. However, few strategies have been elaborated to rationally modulate drug residence time and thereby to integrate this key property into the drug development process. Herein, we show that the interaction between a halogen moiety on an inhibitor and an aromatic residue in the target protein can significantly increase inhibitor residence time.

New approaches for computing ligand-receptor binding kinetics.

The recent and growing evidence that the efficacy of a drug can be correlated to target binding kinetics has seeded the development of a multitude of novel methods aimed at computing rate constants for receptor-ligand binding processes, as well as gaining an understanding of the binding and unbinding pathways and the determinants of structure-kinetic relationships. These new approaches include various types of enhanced sampling molecular dynamics simulations and the combination of energy-based models with chemometric analysis. We assess these approaches in the light of the varying levels of complexity of protein-ligand binding processes.