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Protein-specific HN(CA)CO experiment (Figure 7.41 of "Protein NMR Spectroscopy", 2nd edition) using pre-set values of J-couplings used in the magnetisation transfer stages. The simulation uses the bidirectional propagation method described in (




   parameters.npoints     - a vector of three integers giving the
                            number of points in the three temporal
                            dimensions, ordered as [t1 t2 t3].

   parameters.sweep       - a vector of three real numbers giving
                            the sweep widths in the three frequen-
                            cy dimensions, ordered as [f1 f2 f3].

   H   - Hamiltonian matrix, received from context function

   R   - relaxation superoperator, received from context function

   K   - kinetics superoperator, received from context function


    fid - three-dimensional free induction decay


Below is the output (3D spectrum and three projections) of the HN(CA)CO pulse sequence for the GB1 protein (examples/nmr_proteins/hncano_gb1.m).

Hncaco gb1.png


  1. The sequence is hard-wired to work on 1H,13C,15N proteins and uses PDB labels to select spins that will be affected by otherwise ideal pulses.
  2. Channels: F1 is 15N, F2 is 13C, F3 is 1H.
  3. Spin labels must be set to PDB atom IDs ('CA', 'HA', etc.) in sys.labels for this sequence to work properly

See also

Protein pulse sequences

Version 2.5, authors: Matt Walker, Ilya Kuprov