Determination of the phi angle in a peptide backbone by NMR spectroscopy with a combination of homonuclear and heteronuclear coupling constants.
The phi angle in a cyclic peptide is determined by the combined use of homonuclear and heteronuclear coupling constants. Two of the four coupling constants that define the phi angle in a peptide are determined exactly, two qualitatively. Via Karplus-type equations, they are transformed into dihedral angles and a good agreement is found, allowing for a determination of the phi angle with a certain range of degrees.
Schmieder
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P
Organisch Chemisches Institut der TU München, Garching.
Kessler
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H
D000595:Amino Acid Sequence; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D011487:Protein Conformation