Measurement of one-bond coupling constants


tau = (2JSI)-1; The gradients -G and G are omitted for the first few t1 increments until the delay is large enough to accomodate them. phi and theta are cycled to create four data sets:
  • A ( phi = x, -x) recorded both with theta = psi and theta = psi + pi ,
  • B: ( phi = y, -y). also recorded both with theta = psi and theta = psi + pi

Appropriate linear combinations yield the pairs of echo/antiecho data sets for the two subspectra:
  1. (A - B) theta = psi and
  2. (A + B) theta = psi + pi are echo and antiecho, respectively, for the right multiplet component on Varian Unity spectrometers (left multiplet component on Bruker spectrometers);
  3. (A - B) theta = psi + pi and
  4. (A + B) theta = psi are echo and antiecho, respectively, for the other multiplet component.
psi = x, x, -x, -x; psi ' = y, y, -y, -y.


  • Lerche, M.H., Meissner, A., Poulsen, F.M., and Sørensen, O.W. Pulse sequences for measurement of one-bond 15N-1H coupling constants in the protein backbone J.Magn.Reson. 140 259-263 1999

  • Sørensen, M.D., Meissner, A., and Sørensen, O.W. Spin-state-selective coherence transfer via intermediate states of two-spin coherence in IS spin systems: Application to E.COSY-type measurement of J coupling constants J.Biomol.NMR 10 181-186 1997


Expansion from a 2D S3CT spectrum of 1mM 15N-labeled CI2 in bicelle solution at 37°C. The two subspectra (black and red) are superimposed. Values for 1JNH + 1DNH (upper) and 1JNH (lower) are given next to the peaks.


For Varian and Bruker.

Document: S3CT (index.shtml)
Last modified: 2005-12-19