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Efficient Ensemble Refinement by Reweighting

delete2019-04-02
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OA
AI
J
Jürgen Köfinger
L
Lukas S. Stelzl
K
Klaus Reuter
C
César Allande
K
Katrin Reichel
G
Gerhard Hummer *
DOI:10.1021/acs.jctc.8b01231delete
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Abstract

Abstract

En 中文
Ensemble refinement produces structural ensembles of flexible and dynamic biomolecules by integrating experimental data and molecular simulations. Here we present two efficient numerical methods to solve the computationally challenging maximum-entropy problem arising from a Bayesian formulation of ensemble refinement. Recasting the resulting constrained weight optimization problem into an unconstrained form enables the use of gradient-based algorithms. In two complementary formulations that differ in their dimensionality, we optimize either the log-weights directly or the generalized forces appearing in the explicit analytical form of the solution. We first demonstrate the robustness, accuracy, and efficiency of the two methods using synthetic data. We then use NMR J-couplings to reweight an all-atom molecular dynamics simulation ensemble of the disordered peptide Ala-5 simulated with the AMBER99SB*-ildn-q force field. After reweighting, we find a consistent increase in the population of the polyproline-II conformations and a decrease of alpha-helical-like conformations. Ensemble refinement makes it possible to infer detailed structural models for biomolecules exhibiting significant dynamics, such as intrinsically disordered proteins, by combining input from experiment and simulation in a balanced manner.
Keywords:
CONVERGENCE CONDITIONS
DISORDERED PROTEINS
ANGLE DISTRIBUTIONS
MAXIMUM-ENTROPY
ESCRT-I
DYNAMICS
SIMULATIONS
SPECTROSCOPY
SCATTERING
PEPTIDES
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Journal

Journal of Chemical Theory and Computation cover
Journal of Chemical Theory and Computation
IF:
5.5
Papers:
1.1W
Citations:
5.4W

Organization

G
Goethe University Frankfurt
Scholars:
2.6W
Papers: 2.0W
Citations: 3.0W
M
Max Planck Society
Scholars:
8.2W
Papers: 7.7W
Citations: 3.3W