ISSN:
1573-5001
Keywords:
J coupling
;
Coupling constants
;
Inverse fitting
;
Alanine
;
Helix
;
Peptide
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Summary Alanine-rich peptides serve as models for exploring the factors that control helix structure in peptides and proteins. Scalar CαH-NH couplings (3JHNα) are an extremely useful measure of local helix content; however, the large alanine content in these peptides leads to significant signal overlap in the CαH region of 1H 2D NMR spectra. Quantitative determination of all possible 3JHNα values is, therefore, very challenging. Szyperski and co-workers [(1992) J. Magn. Reson., 99, 552–560] have recently developed a method for determining 3JHNα from NOESY spectra. Because 3JHNα may be determined from 2D peaks outside of the CαH region, there is a much greater likelihood of identifying resolved resonances and measuring the associated coupling constants. It is demonstrated here that 3JHNα can be obtained for every residue in the helical peptide Ac-(AAAAK)3A-NH2. The resulting 3JHNα profile clearly identifies a helical structure in the middle of the peptide and further suggests that the respective helix termini unfold via distinct pathways.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00200434
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