Document Detail


Quantifying millisecond time-scale exchange in proteins by CPMG relaxation dispersion NMR spectroscopy of side-chain carbonyl groups.
MedLine Citation:
PMID:  21681650     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
A new pulse sequence is presented for the measurement of relaxation dispersion profiles quantifying millisecond time-scale exchange dynamics of side-chain carbonyl groups in uniformly (13)C labeled proteins. The methodology has been tested using the 87-residue colicin E7 immunity protein, Im7, which is known to fold via a partially structured low populated intermediate that interconverts with the folded, ground state on the millisecond time-scale. Comparison of exchange parameters extracted for this folding 'reaction' using the present methodology with those obtained from more 'traditional' (15)N and backbone carbonyl probes establishes the utility of the approach. The extracted excited state side-chain carbonyl chemical shifts indicate that the Asx/Glx side-chains are predominantly unstructured in the Im7 folding intermediate. However, several crucial salt-bridges that exist in the native structure appear to be already formed in the excited state, either in part or in full. This information, in concert with that obtained from existing backbone and side-chain methyl relaxation dispersion experiments, will ultimately facilitate a detailed description of the structure of the Im7 folding intermediate.
Authors:
Alexandar L Hansen; Lewis E Kay
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2011-6-18
Journal Detail:
Title:  Journal of biomolecular NMR     Volume:  -     ISSN:  1573-5001     ISO Abbreviation:  -     Publication Date:  2011 Jun 
Date Detail:
Created Date:  2011-6-17     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9110829     Medline TA:  J Biomol NMR     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
Departments of Molecular Genetics, Biochemistry and Chemistry, The University of Toronto, Toronto, ON, M5S 1A8, Canada.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:

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


Previous Document:  Endoscopic bilateral metallic stenting for malignant hilar obstruction using newly designed stents.
Next Document:  Acute Management of Sick Infants with Suspected Inborn Errors of Metabolism.