ISSN:
0749-1581
Keywords:
1H NMR
;
13C NMR
;
Conformational analysis
;
Side-chain conformation
;
z-Filtered relay spectroscopy
;
Homo- and heteronuclear vicinal coupling constants
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The rotamer populations around the C-α - C-β bond of amino acid residues with one β-proton can be calculated from homonuclear and heteronuclear vicinal coupling constants. The measurement of long-range heteronuclear coupling constants, however, suffers from the inherent low sensitivity of the heteronuclear multiple bond experiments. In this paper it is demonstrated that z-filtered homonuclear and heteronuclear relay spectroscopy provides a sensitive and accurate means for the evaluation of conformationally important vicinal coupling constants. Side-chain conformations of the four stereoisomers of β-methylphenylalanine residues in synthetic octapeptide analogues of CCK-8 were derived from the measured coupling constants. This information is not easily available from conformational analysis based on simple steric considerations.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260311208
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