Determination of the j angle in a peptide backbone by NMR spectroscopy with a combination of homonuclear and heteronuclear coupling constants

P. Schmieder, H. Kessler

Biopolymers (1992) 32, 435-440

The j-angle in a cyclic peptide is determined. by the combined use of homonuclear and heteronuclear coupling consts. Two of the four coupling constants that define the j-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 j-angle with a certain range of degrees.