Abstract
Designing a reliable computational methodology to calculate protein:ligand standard binding free energies is extremely challenging. The large change in configurational enthalpy and entropy that accompanies the association of ligand and protein is notoriously difficult to capture in naive brute-force simulations. Addressing this issue, the present protocol rests upon a rigorous statistical mechanical framework for the determination of protein:ligand binding affinities together with the comprehensive Binding Free-Energy Estimator 2 (BFEE2) application software. With the knowledge of the bound state, available from experiments or docking, application of the BFEE2 protocol with a reliable force field supplies in a matter of days standard binding free energies within chemical accuracy, for a broad range of protein:ligand complexes. Limiting undesirable human intervention, BFEE2 assists the end user in preparing all the necessary input files and performing the post-treatment of the simulations towards the final estimate of the binding affinity.
This is a preview of subscription content, access via your institution
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
Data availability
The input and output files of BFEE2 of examples are provided in Supplementary Data. The data shown in Figs. 8–11 were obtained from new simulations, as a way to verify and guarantee the reproducibility of our protocol. Input files for these simulations are available from the corresponding authors upon request.
Code availability
The Python package of BFEE2 can be installed through pip (https://pypi.org/project/BFEE2/) and conda (https://anaconda.org/conda-forge/bfee2). The source code of BFEE2 is available on GitHub (https://github.com/fhh2626/BFEE2)77.
References
Limongelli, V. Ligand binding free energy and kinetics calculation in 2020. WIREs Comput. Mol. Sci. 10, e1455 (2020).
Chodera, J. D. & Mobley, D. L. Entropy-enthalpy compensation: role and ramifications in biomolecular ligand recognition and design. Annu. Rev. Biophys. 42, 121–142 (2013).
Li, A. & Gilson, M. K. Protein-ligand binding enthalpies from near-millisecond simulations: analysis of a preorganization paradox. J. Chem. Phys. 149, 72311 (2018).
de Ruiter, A. & Oostenbrink, C. Advances in the calculation of binding free energies. Curr. Opin. Struct. Biol. 61, 207–212 (2020).
Chipot, C. Frontiers in free-energy calculations of biological systems. Wiley Interdiscip. Rev. Comput. Mol. Sci. 4, 71–89 (2014).
Hermans, J. & Shankar, S. The free energy of xenon binding to myoglobin from molecular dynamics simulation. Isr. J. Chem. 27, 225–227 (1986).
Roux, B., Nina, M., Pomès, R. & Smith, J. C. Thermodynamic stability of water molecules in the bacteriorhodopsin proton channel: a molecular dynamics free energy perturbation study. Biophys. J. 71, 670–681 (1996).
Hermans, J. & Wang, L. Inclusion of loss of translational and rotational freedom in theoretical estimates of free energies of binding. Application to a complex of benzene and mutant T4 lysozyme. J. Am. Chem. Soc. 119, 2707–2714 (1997).
Mann, G. & Hermans, J. Modeling protein–small molecule interactions: structure and thermodynamics of noble gases binding in a cavity in mutant phage T4 lysozyme L99A. J. Mol. Biol. 302, 979–989 (2000).
Boresch, S., Tettinger, F., Leitgeb, M. & Karplus, M. Absolute binding free energies: a quantitative approach for their calculation. J. Phys. Chem. B 107, 9535–9551 (2003).
Deng, Y. & Roux, B. Calculation of standard binding free energies: aromatic molecules in the T4 lysozyme L99A mutant. J. Chem. Theory Comput. 2, 1255–1273 (2006).
Mobley, D. L., Chodera, J. D. & Dill, K. A. On the use of orientational restraints and symmetry corrections in alchemical free energy calculations. J. Chem. Phys. 125, 84902 (2006).
Gilson, M. K., Given, J. A., Bush, B. L. & McCammon, J. A. The statistical-thermodynamic basis for computation of binding affinities: a critical review. Biophys. J. 72, 1047–1069 (1997).
Fu, H., Shao, X., Chipot, C. & Cai, W. Extended adaptive biasing force algorithm. An on-the-fly implementation for accurate free-energy calculations. J. Chem. Theory Comput. 12, 3506–3513 (2016).
Fu, H. et al. Zooming across the free-energy landscape: shaving barriers, and flooding valleys. J. Phys. Chem. Lett. 9, 4738–4745 (2018).
Fu, H., Shao, X., Cai, W. & Chipot, C. Taming rugged free energy landscapes using an average force. Acc. Chem. Res. 52, 3254–3264 (2019).
Fu, H. et al. Finding an optimal pathway on a multidimensional free-energy landscape. J. Chem. Inf. Model. 60, 5366–5374 (2020).
Woo, H.-J. & Roux, B. Calculation of absolute protein–ligand binding free energy from computer simulations. Proc. Natl Acad. Sci. USA 102, 6825–6830 (2005).
Gumbart, J. C., Roux, B. & Chipot, C. Standard binding free energies from computer simulations: what is the best strategy? J. Chem. Theory Comput. 9, 794–802 (2013).
Fu, H., Cai, W., Hénin, J., Roux, B. & Chipot, C. New coarse variables for the accurate determination of standard binding free energies. J. Chem. Theory Comput. 13, 5173–5178 (2017).
Wang, J., Deng, Y. & Roux, B. Absolute binding free energy calculations using molecular dynamics simulations with restraining potentials. Biophys. J. 91, 2798–2814 (2006).
Fu, H. et al. BFEE: a user-friendly graphical interface facilitating absolute binding free-energy calculations. J. Chem. Inf. Model. 58, 556–560 (2018).
Fu, H., Chen, H., Cai, W., Shao, X. & Chipot, C. BFEE2: automated, streamlined, and accurate absolute binding free-energy calculations. J. Chem. Inf. Model. 61, 2116–2123 (2021).
Humphrey, W., Dalke, A. & Schulten, K. VMD: visual molecular dynamics. J. Mol. Graph. 14, 33–38 (1996).
Comer, J. et al. The adaptive biasing force method: everything you always wanted to know but were afraid to ask. J. Phys. Chem. B 119, 1129–1151 (2015).
Zwanzig, R. W. High-temperature equation of state by a perturbation method. I. Nonpolar gases. J. Chem. Phys. 22, 1420–1426 (1954).
Chen, H. et al. Boosting free-energy perturbation calculations with GPU-accelerated namd. J. Chem. Inf. Model. 60, 5301–5307 (2020).
Kirkwood, J. G. Statistical mechanics of fluid mixtures. J. Chem. Phys. 3, 300–313 (1935).
Fiorin, G., Klein, M. L. & Hénin, J. Using collective variables to drive molecular dynamics simulations. Mol. Phys. 111, 3345–3362 (2013).
Zhang, H. et al. Accurate estimation of the standard binding free energy of netropsin with DNA. Molecules 23, 228 (2018).
Du, S. et al. Curvature of buckybowl corannulene enhances its binding to proteins. J. Phys. Chem. C 123, 922–930 (2019).
Sun, H., Li, Y., Tian, S., Wang, J. & Hou, T. P-loop conformation governed crizotinib resistance in G2032R-mutated ROS1 tyrosine kinase: clues from free energy landscape. PLOS Comput. Biol. 10, e1003729 (2014).
Deng, N. et al. Comparing alchemical and physical pathway methods for computing the absolute binding free energy of charged ligands. Phys. Chem. Chem. Phys. 20, 17081–17092 (2018).
Kuusk, A. et al. Adoption of a turn conformation drives the binding affinity of p53 C-terminal domain peptides to 14-3-3σ. ACS Chem. Biol. 15, 262–271 (2020).
Qian, Y. et al. Absolute free energy of binding calculations for macrophage migration inhibitory factor in complex with a druglike inhibitor. J. Phys. Chem. B 123, 8675–8685 (2019).
Comer, J. et al. Beta-1,3 oligoglucans specifically bind to immune receptor CD28 and may enhance T cell activation. Int. J. Mol. Sci. 22, 3124 (2021).
Velez-Vega, C. & Gilson, M. K. Overcoming dissipation in the calculation of standard binding free energies by ligand extraction. J. Comput. Chem. 34, 2360–2371 (2013).
Liu, H., Fu, H., Chipot, C., Shao, X. & Cai, W. Accuracy of alternate nonpolarizable force fields for the determination of protein–ligand binding affinities dominated by cation−π interactions. J. Chem. Theory Comput. 17, 3908–3915 (2021).
Srinivasan, J., Cheatham, T. E., Cieplak, P., Kollman, P. A. & Case, D. A. Continuum solvent studies of the stability of DNA, RNA, and phosphoramidate–DNA helices. J. Am. Chem. Soc. 120, 9401–9409 (1998).
Limongelli, V., Bonomi, M. & Parrinello, M. Funnel metadynamics as accurate binding free-energy method. Proc. Natl Acad. Sci. USA 110, 6358–6363 (2013).
Laio, A. & Parrinello, M. Escaping free-energy minima. Proc. Natl Acad. Sci. USA 99, 12562–12566 (2002).
Raniolo, S. & Limongelli, V. Ligand binding free-energy calculations with funnel metadynamics. Nat. Protoc. 15, 2837–2866 (2020).
Mobley, D. L., Chodera, J. D. & Dill, K. A. Confine-and-release method: obtaining correct binding free energies in the presence of protein conformational change. J. Chem. Theory Comput. 3, 1231–1235 (2007).
Miao, Y., Bhattarai, A. & Wang, J. Ligand Gaussian accelerated molecular dynamics (LiGaMD): characterization of ligand binding thermodynamics and kinetics. J. Chem. Theory Comput. 16, 5526–5547 (2020).
Wang, L., Friesner, R. A. & Berne, B. J. Replica exchange with solute scaling: a more efficient version of replica exchange with solute tempering (REST2). J. Phys. Chem. B 115, 9431–9438 (2011).
Kofke, D. A. & Cummings, P. T. Precision and accuracy of staged free-energy perturbation methods for computing the chemical potential by molecular simulation. Fluid Phase Equilib 150–151, 41–49 (1998).
Huang, J. et al. CHARMM36m: an improved force field for folded and intrinsically disordered proteins. Nat. Methods 14, 71–73 (2017).
Tian, C. et al. ff19SB: amino-acid-specific protein backbone parameters trained against quantum mechanics energy surfaces in solution. J. Chem. Theory Comput. 16, 528–552 (2020).
Lemkul, J. A., Huang, J., Roux, B. & MacKerell, A. D. An empirical polarizable force field based on the classical drude oscillator model: development history and recent applications. Chem. Rev. 116, 4983–5013 (2016).
Ponder, J. W. et al. Current status of the AMOEBA polarizable force field. J. Phys. Chem. B 114, 2549–2564 (2010).
Jo, S. & Jiang, W. A generic implementation of replica exchange with solute tempering (REST2) algorithm in NAMD for complex biophysical simulations. Comput. Phys. Commun. 197, 304–311 (2015).
Deng, Y. & Roux, B. Computation of binding free energy with molecular dynamics and grand canonical monte carlo simulations. J. Chem. Phys. 128, 115103 (2008).
Ben-Shalom, I. Y., Lin, C., Kurtzman, T., Walker, R. C. & Gilson, M. K. Simulating water exchange to buried binding sites. J. Chem. Theory Comput. 15, 2684–2691 (2019).
Jo, S., Kim, T., Iyer, V. G. & Im, W. CHARMM-GUI: a web-based graphical user interface for CHARMM. J. Comput. Chem. 29, 1859–1865 (2008).
Case, D. A. et al. Amber 2021 (University of California, San Francisco, 2021).
Liu, P., Dehez, F., Cai, W. & Chipot, C. A toolkit for the analysis of free-energy perturbation calculations. J. Chem. Theory Comput. 8, 2606–2616 (2012).
Phillips, J. C. et al. Scalable molecular dynamics on CPU and GPU architectures with NAMD. J. Chem. Phys. 153, 44130 (2020).
Abraham, M. J. et al. GROMACS: high performance molecular simulations through multi-level parallelism from laptops to supercomputers. SoftwareX 1–2, 19–25 (2015).
Hénin, J. & Chipot, C. Overcoming free energy barriers using unconstrained molecular dynamics simulations. J. Chem. Phys. 121, 2904–2914 (2004).
Pisabarro, M. T. & Serrano, L. Rational design of specific high-affinity peptide ligands for the Abl-SH3 domain. Biochemistry 35, 10634–10640 (1996).
Pohorille, A., Jarzynski, C. & Chipot, C. Good practices in free-energy calculations. J. Phys. Chem. B 114, 10235–10253 (2010).
Hahn, A. M. & Then, H. Characteristic of Bennett’s acceptance ratio method. Phys. Rev. E 80, 031111 (2009).
Bennett, C. H. Efficient estimation of free energy differences from Monte Carlo data. J. Comput. Phys. 22, 245–268 (1976).
Brown, S. P. & Muchmore, S. W. Large-scale application of high-throughput molecular mechanics with Poisson–Boltzmann surface area for routine physics-based scoring of protein–ligand complexes. J. Med. Chem. 52, 3159–3165 (2009).
Morton, A. & Matthews, B. W. Specificity of ligand binding in a buried nonpolar cavity of T4 lysozyme: linkage of dynamics and structural plasticity. Biochemistry 34, 8576–8588 (1995).
Mares-Guia, M., Nelson, D. L. & Rogana, E. Electronic effects in the interaction of para-substituted benzamidines with trypsin: the involvement of the π-electronic density at the central atom of the substituent in binding. J. Am. Chem. Soc. 99, 2331–2336 (1977).
Katz, B. A. et al. Structural basis for selectivity of a small molecule, S1-binding, submicromolar inhibitor of urokinase-type plasminogen activator. Chem. Biol. 7, 299–312 (2000).
Schwarzl, S. M., Tschopp, T. B., Smith, J. C. & Fischer, S. Can the calculation of ligand binding free energies be improved with continuum solvent electrostatics and an ideal-gas entropy correction? J. Comput. Chem. 23, 1143–1149 (2002).
Schärer, K. et al. Quantification of cation–π interactions in protein–ligand complexes: crystal-structure analysis of Factor Xa bound to a quaternary ammonium ion ligand. Angew. Chemie Int. Ed. 44, 4400–4404 (2005).
Khan, H. M., MacKerell, A. D. & Reuter, N. Cation–π interactions between methylated ammonium groups and tryptophan in the CHARMM36 additive force field. J. Chem. Theory Comput. 15, 7–12 (2019).
Liu, H., Fu, H., Shao, X., Cai, W. & Chipot, C. Accurate description of cation–π interactions in proteins with a nonpolarizable force field at no additional cost. J. Chem. Theory Comput. 16, 6397–6407 (2020).
Bingham, R. J. et al. Thermodynamics of binding of 2-methoxy-3-isopropylpyrazine and 2-methoxy-3-isobutylpyrazine to the major urinary protein. J. Am. Chem. Soc. 126, 1675–1681 (2004).
Timm, D. E., Baker, L. J., Mueller, H., Zidek, L. & Novotny, M. V. Structural basis of pheromone binding to mouse major urinary protein (MUP-I). Protein Sci 10, 997–1004 (2001).
Christopher, J. A. et al. Biophysical fragment screening of the β1-adrenergic receptor: identification of high affinity arylpiperazine leads using structure-based drug design. J. Med. Chem. 56, 3446–3455 (2013).
Singharoy, A., Chipot, C., Moradi, M. & Schulten, K. Chemomechanical coupling in hexameric protein–protein interfaces harnesses energy within V-type atpases. J. Am. Chem. Soc. 139, 293–310 (2017).
Adachi, K., Oiwa, K., Yoshida, M., Nishizaka, T. & Kinosita, K. Controlled rotation of the F1-ATPase reveals differential and continuous binding changes for ATP synthesis. Nat. Commun. 3, 1022 (2012).
Fu, H. et al. Accurate determination of protein:ligand standard binding free energies from molecular dynamics simulations. BFEE2: Binding free energy estimator 2. https://doi.org/10.5281/zenodo.5501842 (2021).
Liu, H., Okazaki, S. & Shinoda, W. Heteroaryldihydropyrimidines alter capsid assembly by adjusting the binding affinity and pattern of the hepatitis B virus core protein. J. Chem. Inf. Model. 59, 5104–5110 (2019).
Miao, M. et al. Avoiding non-equilibrium effects in adaptive biasing force calculations. Mol. Simul. 47, 390–394 (2021).
Samways, M. L., Bruce Macdonald, H. E. & Essex, J. W. Grand: a Python module for grand canonical water sampling in OpenMM. J. Chem. Inf. Model. 60, 4436–4441 (2020).
Acknowledgements
This study was supported by the National Natural Science Foundation of China (22073050, 22174075 and 22103041), the China Post-doctoral Science Foundation (bs6619012), Frontiers Science Center for New Organic Matter, Nankai University (63181206), the US National Institutes of Health (R01-AI148740), the National Science Foundation (NSF) through grant no. MCB-1517221, the France and Chicago Collaborating in The Sciences (FACCTS) program, and the Agence Nationale de la Recherche (ProteaseInAction). J.C.G. acknowledges computational resources provided through the Extreme Science and Engineering Discovery Environment (XSEDE; TG-MCB130173). The paper is dedicated to the 100th anniversary of Chemistry at Nankai University.
Author information
Authors and Affiliations
Contributions
H.F., X.S., W.S. and C.C. conceived the project. H.F. designed the BFEE2 software and implemented the workflow of binding free-energy calculations. H.C. implemented the Gromacs support of BFEE2. H.F., M.B., F.S., E.G.C.D, A.P., F.D. and J.C.G. tested the software. H.F., B.R., W.S. and C.C. wrote the manuscript.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Peer review
Peer review information
Nature Protocols thanks Nanjie Deng and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Related links
Key references using this protocol
Woo, H. et al. Proc. Natl Acad. Sci. USA 102, 6825–6830 (2005): https://doi.org/10.1073/pnas.0409005102
Gumbart, J. C. et al. J. Chem. Theory Comput. 9, 794–802 (2013): https://doi.org/10.1021/ct3008099
Fu, H. et al. J. Chem. Theory Comput. 13, 5173–5178 (2017): https://doi.org/10.1021/acs.jctc.7b00791
Fu, H. et al. Acc. Chem. Res. 52, 3254–3264 (2019): https://doi.org/10.1021/acs.accounts.9b00473
Fu, H. et al. J. Chem. Inf. Model. 61, 2116–2123 (2021): https://doi.org/10.1021/acs.jcim.1c00269
Supplementary information
Supplementary Information
Supplementary Figs. 1–14, Supplementary Protocols, Supplementary Tables 1–4 and Supplementary References.
Supplementary Data
Files required to follow the protocol
Rights and permissions
About this article
Cite this article
Fu, H., Chen, H., Blazhynska, M. et al. Accurate determination of protein:ligand standard binding free energies from molecular dynamics simulations. Nat Protoc 17, 1114–1141 (2022). https://doi.org/10.1038/s41596-021-00676-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41596-021-00676-1
This article is cited by
-
Mutagenesis and structural studies reveal the basis for the specific binding of SARS-CoV-2 SL3 RNA element with human TIA1 protein
Nature Communications (2023)
-
Towards a purely physics-based computational binding affinity estimation
Nature Computational Science (2023)
-
Binding affinity estimation from restrained umbrella sampling simulations
Nature Computational Science (2022)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.