Related ArticlesSecondary structural effects on protein NMR chemical shifts.
J Biomol NMR. 2004 Nov;30(3):233-44
Authors: Wang Y
For an amino acid in protein, its chemical shift, delta(phi, psi)(s), is expressed as a function of its backbone torsion angles (phi and psi) and secondary state (s): delta(phi, psi)(s=deltaphi, psi)_coil+Deltadelta(phi, psi)_s), where delta(phi, psi)(coil) represents its chemical shift at coil state (s=coil); Delta delta(phi, psi)(s) (s=sheet or helix) is herein defined as secondary structural effect correction factor, which are quantitatively determined from Residue-specific Secondary Structure Shielding Surface (RSS) for (13)CO, (13)Calpha, (13)Cbeta,(1)Halpha, (15)N, and (1)HN nuclei. The secondary structural effect correction factors defined in this study differ from those in earlier investigations by separating out the backbone conformational effects. As a consequence, their magnitudes are significantly smaller than those earlier reported. The present Delta delta(phi, psi)(sheet) and Delta delta(phi, psi)(helix) were found varying little with backbone conformation and the 20 amino acids, specifically for (13)CO, (13)Calpha, and (1)Halpha nuclei. This study also carries out some useful investigations on other chemical shift prediction approaches - the traditional shielding surfaces, SHIFTS, SHIFTX, PROSHIFT, and identifies some unexpected shortcomings with these methods. It provides some useful insights into understanding protein chemical shifts and suggests a new route to improving chemical shifts prediction. The RSS surfaces were incorporated into the program PRSI.
[NMR paper] Secondary and tertiary structural effects on protein NMR chemical shifts: an ab initi
Secondary and tertiary structural effects on protein NMR chemical shifts: an ab initio approach.
Related Articles Secondary and tertiary structural effects on protein NMR chemical shifts: an ab initio approach.
Science. 1993 Jun 4;260(5113):1491-6
Authors: de Dios AC, Pearson JG, Oldfield E
Recent theoretical developments permit the prediction of 1H, 13C, 15N, and 19F nuclear magnetic resonance chemical shifts in proteins and offer new ways of analyzing secondary and tertiary structure as well as for probing protein electrostatics. For 13C,...
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08-21-2010 11:53 PM
Using NMR Chemical Shifts as Structural Restraints in Molecular Dynamics Simulations
Using NMR Chemical Shifts as Structural Restraints in Molecular Dynamics Simulations of Proteins.
Related Articles Using NMR Chemical Shifts as Structural Restraints in Molecular Dynamics Simulations of Proteins.
Structure. 2010 Aug 11;18(8):923-933
Authors: Robustelli P, Kohlhoff K, Cavalli A, Vendruscolo M
We introduce a procedure to determine the structures of proteins by incorporating NMR chemical shifts as structural restraints in molecular dynamics simulations. In this approach, the chemical shifts are expressed as differentiable...
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08-17-2010 03:36 AM
Use of chemical shifts for structural studies of nucleic acids
Use of chemical shifts for structural studies of nucleic acids
Publication year: 2010
Source: Progress in Nuclear Magnetic Resonance Spectroscopy, In Press, Accepted Manuscript, Available online 1 February 2010</br>
Sik Lok, Lam , Lai Man, Chi</br>
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08-16-2010 03:50 AM
Mapping of protein structural ensembles by chemical shifts
Abstract Applying the chemical shift prediction programs SHIFTX and SHIFTS to a data base of protein structures with known chemical shifts we show that the averaged chemical shifts predicted from the structural ensembles explain better the experimental data than the lowest energy structures. This is in agreement with the fact that proteins in solution occur in multiple conformational states in fast exchange on the chemical shift time scale. However, in contrast to the real conditions in solution at ambient temperatures, the standard NMR structural calculation methods as well chemical shift...
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08-14-2010 04:19 AM
Sequential nearest-neighbor effects on computed 13Cα chemical shifts
Abstract To evaluate sequential nearest-neighbor effects on quantum-chemical calculations of 13Cα chemical shifts, we selected the structure of the nucleic acid binding (NAB) protein from the SARS coronavirus determined by NMR in solution (PDB id 2K87). NAB is a 116-residue α/β protein, which contains 9 prolines and has 50% of its residues located in loops and turns. Overall, the results presented here show that sizeable nearest-neighbor effects are seen only for residues preceding proline, where Pro introduces an overestimation, on average, of 1.73 ppm in the computed 13Cα chemical...
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08-14-2010 04:19 AM
The predictive accuracy of secondary chemical shifts is more affected by protein seco
Abstract Biomolecular NMR spectroscopy frequently employs estimates of protein secondary structure using secondary chemical shift (Î?δ) values, measured as the difference between experimental and random coil chemical shifts (RCCS). Most published random coil data have been determined in aqueous conditions, reasonable for non-membrane proteins, but potentially less relevant for membrane proteins. Two new RCCS sets are presented here, determined in dimethyl sulfoxide (DMSO) and chloroform:methanol:water (4:4:1 by volume) at 298 K. A web-based program, CS-CHEMeleon, has been implemented to...
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08-14-2010 04:19 AM
PSSI: secondary structure from chemical shifts
Link to PSSI program
Reference and abstract:
Probability-based protein secondary structure identification using combined NMR chemical-shift data.
Wang Y, Jardetzky O.
Division of Chemical Biology, Department of Molecular Pharmacology, Stanford University, Stanford, California 94305, USA.