The O-17-NMR shielding range and shielding time scale and detection of discrete hydrogen-bonded conformational states in peptides
(EN)
Gerothanassis, I. P.
(EN)
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας
(EL)
Gerothanassis, I. P.
(EN)
The O-17-NMR shielding range and shielding time scale due to hydrogen-bonding interactions in peptides are critically evaluated relative to those of H-1-NMR. Furthermore, the assumptions and conclusions in previous O-17-NMR studies on the detection of discrete conformational states in peptides (V. Tsikaris et al., Biopolymers, 2000, Vol. 53, pp. 135-139) are reconsidered. Consistent examination of the method demonstrates that although O-17 shieldings of peptide oxygens are very sensitive to hydrogen bonding interactions, the O-17-NMR shielding time scale is not advantageous compared to that of H-1-NMR, and thus it is not suitable for the detection of discrete hydrogen-bonded conformational states in peptides. O-17-NMR spectroscopy is prone to interpretation errors due to the formation of O-17-labeled impurities during the synthetic procedures (A. Steinschneider et al., International Journal of Peptide and Protein Research, 1981, Vol. 18 pp. 324-333). (C) 2001 John Wiley & Sons, Inc.
(EN)
