Empirical ³J_CO-CB values and angular backbone constraints can be interconverted following well-known Karplus relationships: , 98JB199 , 99JB263 .

³J_CO-CB=2.54*cos²(fi-120) - 0.55*cos(fi-120) + 0.37 ³J_CO-CB=1.61*cos²(fi-120) - 0.66*cos(fi-120) + 0.26 ( 97JACS6360 ) ³J_CO-CB=2.72*cos²(fi-120) - 0.31*cos(fi-120) + 0.39 ( 99JB1-14 )

where fi is the backbone torsion angle.

 Range from 0 Hz to +4.0 Hz

• Simultaneous measurement of COCB and COCG from a quantitative J-correlation 3D HN(CO)C experiment.
• 98JB199 (ecosy)
• 3D H(N)CA,CO[CB]-E.COSY in ¹³C,¹⁵N-labeled proteins in H₂O.
• HNCACB-E.COSY experiment ( 99JB263 )

Application of in the study of side-chain conformation in an unfolded protein ( 99JMB705 ).

 The same dihedral angle information can be obtained from other coupling constants values: