[NMR paper] Optimization of the additive CHARMM all-atom protein force field targeting improved sampling of the backbone ?, ? and side-chain ?(1) and ?(2) dihedral angles.
Optimization of the additive CHARMM all-atom protein force field targeting improved sampling of the backbone ?, ? and side-chain ?(1) and ?(2) dihedral angles.
Related ArticlesOptimization of the additive CHARMM all-atom protein force field targeting improved sampling of the backbone ?, ? and side-chain ?(1) and ?(2) dihedral angles.
Authors: Best RB, Zhu X, Shim J, Lopes PE, Mittal J, Feig M, Mackerell AD
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 ?-helix and extended regions of the Ramachandran map, correcting the ?-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.
PMID: 23341755 [PubMed - as supplied by publisher]
PPM: a side-chain and backbone chemical shift predictor for the assessment of protein conformational ensembles
PPM: a side-chain and backbone chemical shift predictor for the assessment of protein conformational ensembles
Abstract The combination of the wide availability of protein backbone and side-chain NMR chemical shifts with advances in understanding of their relationship to protein structure makes these parameters useful for the assessment of structural-dynamic protein models. A new chemical shift predictor (PPM) is introduced, which is solely based on physicalâ??chemical contributions to the chemical shifts for both the protein backbone and methyl-bearing amino-acid side chains. To...
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[NMR paper] Residual backbone and side-chain 13C and 15N resonance assignments of the intrinsic t
Residual backbone and side-chain 13C and 15N resonance assignments of the intrinsic transmembrane light-harvesting 2 protein complex by solid-state Magic Angle Spinning NMR spectroscopy.
Related Articles Residual backbone and side-chain 13C and 15N resonance assignments of the intrinsic transmembrane light-harvesting 2 protein complex by solid-state Magic Angle Spinning NMR spectroscopy.
J Biomol NMR. 2005 Apr;31(4):279-93
Authors: Gammeren AJ, Hulsbergen FB, Hollander JG, Groot HJ
This study reports the sequence specific chemical shifts...
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11-25-2010 08:21 PM
[NMR paper] Backbone and side-chain heteronuclear resonance assignments and hyperfine NMR shifts
Backbone and side-chain heteronuclear resonance assignments and hyperfine NMR shifts in horse cytochrome c.
Related Articles Backbone and side-chain heteronuclear resonance assignments and hyperfine NMR shifts in horse cytochrome c.
Protein Sci. 2003 Sep;12(9):2104-8
Authors: Liu W, Rumbley J, Englander SW, Wand AJ
The mutant of horse heart cytochrome c was expressed in E. coli during growth on isotopically enriched minimal media. Complete resonance assignments of both the diamagnetic reduced (spin zero) and paramagnetic oxidized (spin (1/2))...
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[NMR paper] Automated NMR determination of protein backbone dihedral angles from cross-correlated
Automated NMR determination of protein backbone dihedral angles from cross-correlated spin relaxation.
Related Articles Automated NMR determination of protein backbone dihedral angles from cross-correlated spin relaxation.
J Biomol NMR. 2002 Apr;22(4):349-63
Authors: Kloiber K, Schüler W, Konrat R
The simultaneous interpretation of a suite of dipole-dipole and dipole-CSA cross-correlation rates involving the backbone nuclei 13Calpha, 1Halpha, 13CO, 15N and 1HN can be used to resolve the ambiguities associated with each individual...
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[NMR paper] Backbone and side-chain 13C and 15N signal assignments of the alpha-spectrin SH3 doma
Backbone and side-chain 13C and 15N signal assignments of the alpha-spectrin SH3 domain by magic angle spinning solid-state NMR at 17.6 Tesla.
Related Articles Backbone and side-chain 13C and 15N signal assignments of the alpha-spectrin SH3 domain by magic angle spinning solid-state NMR at 17.6 Tesla.
Chembiochem. 2001 Apr 2;2(4):272-81
Authors: Pauli J, Baldus M, van Rossum B, de Groot H, Oschkinat H
The backbone and side-chain 13C and 15N signals of a solid 62-residue (u-13C,15N)-labelled protein containing the alpha-spectrin SH3 domain were...
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Site-Specific Protein Backbone and Side-Chain NMR Chemical Shift and Relaxation Analy
Site-Specific Protein Backbone and Side-Chain NMR Chemical Shift and Relaxation Analysis of Human Vinexin SH3 Domain using a Genetically Encoded (15)N/(19)F-Labeled Unnatural Amino Acid.
Related Articles Site-Specific Protein Backbone and Side-Chain NMR Chemical Shift and Relaxation Analysis of Human Vinexin SH3 Domain using a Genetically Encoded (15)N/(19)F-Labeled Unnatural Amino Acid.
Biochem Biophys Res Commun. 2010 Oct 11;
Authors: Shi P, Xi Z, Wang H, Shi C, Xiong Y, Tian C
SH3 is a ubiquitous domain mediating protein-protein interactions....
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[NMR paper] NMR characterization of side chain flexibility and backbone structure in the type I a
NMR characterization of side chain flexibility and backbone structure in the type I antifreeze protein at near freezing temperatures.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--pubs.acs.org-images-acspubs.jpg Related Articles NMR characterization of side chain flexibility and backbone structure in the type I antifreeze protein at near freezing temperatures.
Biochemistry. 1996 Dec 24;35(51):16698-704
Authors: Gronwald W, Chao H, Reddy DV, Davies PL, Sykes BD, Sönnichsen FD
The flexibility of the polar side chains in the...
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[NMR paper] Comparison of backbone and tryptophan side-chain dynamics of reduced and oxidized Esc
Comparison of backbone and tryptophan side-chain dynamics of reduced and oxidized Escherichia coli thioredoxin using 15N NMR relaxation measurements.
Related Articles Comparison of backbone and tryptophan side-chain dynamics of reduced and oxidized Escherichia coli thioredoxin using 15N NMR relaxation measurements.
Biochemistry. 1993 Jan 19;32(2):426-35
Authors: Stone MJ, Chandrasekhar K, Holmgren A, Wright PE, Dyson HJ
The backbone and tryptophan side-chain dynamics of both the reduced and oxidized forms of uniformly 15N-labeled Escherichia...
Optimization of the additive CHARMM all-atom protein force field targeting improved sampling of the backbone ?, ? and side-chain ?(1) and ?(2) dihedral angles.
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