Document Detail


Accurate prediction of proton chemical shifts. II. Peptide analogues.
MedLine Citation:
PMID:  11908086     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Proton chemical shifts of eight cyclic amide molecules were measured in DMSO and D2O solutions. The magnetic shieldings of the corresponding aliphatic, aromatic, and amide protons were calculated by Hartree-Fock and DFT, using the 6-311G**, 6-311++G**, and TZVP basis sets. For aliphatic protons, all of these methods reproduce the experimental values in DMSO solutions excellently after linear regression. The Hartree-Fock method tends to give slightly better agreement than DFT. The best performance is given by the HF/6-311G** method, with an rms deviation of 0.068 ppm. The deviations from experimental chemical shifts in D2O solutions are only slightly larger than those in DMSO solutions. This suggests that we can use the calculated gas phase proton chemical shifts directly to predict experimental data in various solvents, including water. For amide protons, which exchange with water and form hydrogen bonds with DMSO, only modest agreement is obtained, as expected. The present studies confirm that the GIAO approach can reach high accuracy for the relative chemical shifts of aliphatic and aromatic protons at a low cost. Such calculations may provide constraints for the conformational analysis of proteins and other macromolecules.
Authors:
Bing Wang; James F Hinton; Peter Pulay
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Journal of computational chemistry     Volume:  23     ISSN:  0192-8651     ISO Abbreviation:  J Comput Chem     Publication Date:  2002 Mar 
Date Detail:
Created Date:  2002-03-22     Completed Date:  2002-10-24     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9878362     Medline TA:  J Comput Chem     Country:  United States    
Other Details:
Languages:  eng     Pagination:  492-7     Citation Subset:  IM    
Affiliation:
Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701, USA.
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MeSH Terms
Descriptor/Qualifier:
Amides / chemistry
Amino Acids, Cyclic / chemistry*
Nuclear Magnetic Resonance, Biomolecular / methods*
Peptides / chemistry
Protons
Solvents
Chemical
Reg. No./Substance:
0/Amides; 0/Amino Acids, Cyclic; 0/Peptides; 0/Protons; 0/Solvents

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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