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An ω 1 ‐band‐selective, ω 1 ‐homonuclear decoupled ROESY experiment: application to the assignment of 1 H NMR spectra of difficult‐to‐assign peptide sequences
Author(s) -
Kaerner Andreas,
Rabenstein Dallas L.
Publication year - 1998
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/(sici)1097-458x(199808)36:8<601::aid-omr342>3.0.co;2-c
Subject(s) - homonuclear molecule , chemistry , pulse sequence , decoupling (probability) , spectral line , peptide , stereochemistry , proton nmr , nuclear magnetic resonance , molecule , physics , biochemistry , organic chemistry , control engineering , astronomy , engineering
Application of an ω 1 ‐band‐selective, ω 1 ‐homonuclear decoupled ROESY (BASHD‐ROESY) experiment to the assignment of 1 H NMR spectra of peptides is demonstrated. Band selection in the ω 1 dimension is achieved with the double pulsed field gradient spin echo (DPFGSE) technique; homonuclear decoupling in the ω 1 dimension is achieved by placing a non‐selective 180° pulse together with the first half of the DPFGSE in the middle of the evolution period. Application of the BASHD‐ROESY experiment is demonstrated with the complete assignment of the proton resonances of the synthetic 19 amino acid peptide N ‐Ac–Ala–Glu–Ala–Ala– Ala–Arg–Ala–Ala–Ala–Arg–Arg–Ala–Ala– Arg–Arg–Ala–Ala–Ala–Arg–NH 2 . Critical to making the assignments was the significantly increased resolution in the C α H–NH region of the ROESY spectrum measured with the BASHD‐ROESY pulse sequence with band selection and homonuclear decoupling in the C α H region. NOEs observed for the peptide indicate it has a helical secondary structure in solution. © 1998 John Wiley & Sons, Ltd.