Abstract
Enhanced sampling methods such as metadynamics and umbrella sampling have become essential tools for exploring the configuration space of molecules and materials. At the same time, they have long faced a number of issues such as the inefficiency when dealing with a large number of collective variables (CVs) or systems with high free energy barriers. Here we show that, with clustering and adaptive tuning techniques, the reinforced dynamics (RiD) scheme can be used to efficiently explore the configuration space and free energy landscapes with a large number of CVs or systems with high free energy barriers. We illustrate this by studying various representative and challenging examples. First we demonstrate the efficiency of adaptive RiD compared with other methods and construct the nine-dimensional (9D) free energy landscape of a peptoid trimer, which has energy barriers of more than 8 kcal mol−1. We then study the folding of the protein chignolin using 18 CVs. In this case, both the folding and unfolding rates are observed to be 4.30 μs−1. Finally, we propose a protein structure refinement protocol based on RiD. This protocol allows us to efficiently employ more than 100 CVs for exploring the landscape of protein structures and it gives rise to an overall improvement of 14.6 units over the initial global distance test–high accuracy (GDT-HA) score.
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Data availability
The initial files of all examples for running adaptive RiD are available from Zenodo63. Our peptoid models come from Weiser’s work32. Our chignolin model is obtained from the Protein Data Bank (PDB 5AWL). The MD trajectories of chignolin from Anton can be obtained from ref. 36. The targets in CASP13 can be obtained from the official CASP list (https://predictioncenter.org/casp13/targetlist.cgi). The Markov state models of R0974s1, R0986s1 and R1002-D2 can be obtained from the work of Heo and colleagues47. The input PLUMED2 files are available via Plumed Nest under plumID:21.034. Source data are provided with this paper.
Code availability
Python implementations of our codes are available at GitHub (https://github.com/dongdawn/rid) and Zenodo64.
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Acknowledgements
The work of D.W., L.Z. and W.E is supported in part by a gift from iFlytek to Princeton University. The work of H.W. is supported by the National Science Foundation of China under grant no.11871110 and Beijing Academy of Artificial Intelligence (BAAI). The work of L.Z. is also supported by the DOE Center of Chemistry in Solutions and at Interfaces (CSI) through award no. DE-SC0019394.
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D.W., L.Z., H.W. and W.E. conceptualized the research. D.W., Y.W. and J.C. conducted the research and performed data analysis. D.W. L.Z., H.W. and W.E. drafted the manuscript. All authors commented on and revised the manuscript.
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Nature Computational Science thanks Vojtech Spiwok, Max Bonomi and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Handling editor: Jie Pan, in collaboration with the Nature Computational Science team.
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Wang, D., Wang, Y., Chang, J. et al. Efficient sampling of high-dimensional free energy landscapes using adaptive reinforced dynamics. Nat Comput Sci 2, 20–29 (2022). https://doi.org/10.1038/s43588-021-00173-1
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DOI: https://doi.org/10.1038/s43588-021-00173-1
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