Evidence map›Paper›PMID 23341755›Full record

ArticleJournal of chemical theory and computation2012

Optimization of the additive CHARMM all-atom protein force field targeting improved sampling of the backbone φ, ψ and side-chain χ(1) and χ(2) dihedral angles.

Robert B Best, Xiao Zhu, Jihyun Shim, Pedro E M Lopes, Jeetain Mittal, Michael Feig, Alexander D Mackerell

Abstract read
In one paragraph

Article in Journal of chemical theory and computation, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2,334 papers.

0numbers the graph read from it
0cells of the map it votes in
2,334citing papers in PubMed
37.2field-weighted citation impact, top 1% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2,334 citing papers in PubMed, 4,665 citations in OpenAlex.

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2,274 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors at 4 institutions in 2 countries.

Robert B BestUniversity of Cambridge, Department of Chemistry, Lensfield Road, Cambridge CB2 1EW.
Xiao Zhu
Jihyun Shim
Pedro E M Lopes
Jeetain Mittal
Michael Feig
Alexander D Mackerell
University of Maryland, Baltimore · USLehigh University · USMichigan State University · USUniversity of Cambridge · GB

Funding

Polarizable Force Field for Proteins and LipidsR01GM072558 · NIGMS · WEILL MEDICAL COLLEGE OF CORNELL UNIV · PI ROUX, BENOIT · 2005 to 2023
$5.1M
Oligonucleotide Conformational HeterogeneityR01GM051501 · NIGMS · UNIVERSITY OF MARYLAND BALTIMORE · PI MACKERELL, ALEXANDER D · 2003 to 2018
$3.6M
Protein structure refinement through effective sampling and scoringR01GM084953 · NIGMS · MICHIGAN STATE UNIVERSITY · PI FEIG, MICHAEL · 2008 to 2017
$2.5M
Multiscale modeling of supramolecular protein-DNA assembliesR01GM092949 · NIGMS · MICHIGAN STATE UNIVERSITY · PI FEIG, MICHAEL · 2010 to 2013
$1.1M
HALOGEN FREE ENERGY DATABASE FOR RATIONAL DRUG DESIGNR29GM051501 · NIGMS · UNIVERSITY OF MARYLAND BALTIMORE · PI MACKERELL, ALEXANDER D. · 1996 to 2000
$108k
NIGMS NIH HHS R01 GM051501NIGMS NIH HHS R01 GM072558NIGMS NIH HHS R01 GM084953NIGMS NIH HHS R01 GM092949NIGMS NIH HHS R29 GM051501
6 · The paper itself

Abstract

While the quality of the current CHARMM22/CMAP additive force field for proteins has been demonstrated in a large number of applications, limitations in the model with respect to the equilibrium between the sampling of helical and extended conformations in folding simulations have been noted. To overcome this, as well as make other improvements in the model, we present a combination of refinements that should result in enhanced accuracy in simulations of proteins. The common (non Gly, Pro) backbone CMAP potential has been refined against experimental solution NMR data for weakly structured peptides, resulting in a rebalancing of the energies of the α-helix and extended regions of the Ramachandran map, correcting the α-helical bias of CHARMM22/CMAP. The Gly and Pro CMAPs have been refitted to more accurate quantum-mechanical energy surfaces. Side-chain torsion parameters have been optimized by fitting to backbone-dependent quantum-mechanical energy surfaces, followed by additional empirical optimization targeting NMR scalar couplings for unfolded proteins. A comprehensive validation of the revised force field was then performed against data not used to guide parametrization: (i) comparison of simulations of eight proteins in their crystal environments with crystal structures; (ii) comparison with backbone scalar couplings for weakly structured peptides; (iii) comparison with NMR residual dipolar couplings and scalar couplings for both backbone and side-chains in folded proteins; (iv) equilibrium folding of mini-proteins. The results indicate that the revised CHARMM 36 parameters represent an improved model for the modeling and simulation studies of proteins, including studies of protein folding, assembly and functionally relevant conformational changes.

Identifiers

PMID23341755
PMCPMC3549273
OpenAlexW2060872117

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.