hncoca.m

Magnitude-mode HNCOCA pulse sequence from

               http://dx.doi.org/10.1007/BF01874573

using the bidirectional propagation method described in

            http://dx.doi.org/10.1016/j.jmr.2014.04.002

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. F1 is N, F2 is CA, F3 is H.

Syntax

    fid=hncoca(spin_system,parameters,H,R,K)

Parameters

     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].

     parameters.tau       - the four delays required for the ope-
                            ration of the sequence (see the paper)
                            in seconds. Reasonable values are
                            [2.25e-3, 2.75e-3, 8.00e-3, 7.00e-3]

   H   - Hamiltonian matrix, received from context function

   R   - relaxation superoperator, received from context function

   K   - kinetics superoperator, received from context function

Outputs

   fid - three-dimensional free induction decay

Examples

HNCOCA simulation for ubiquitin (examples/nmr_proteins/hncoca_ubiquitin_theo.m) appears below.

Notes

Spin labels must be set to PDB atom IDs ('CA', 'HA', etc.) in sys.labels for this sequence to work properly.

See also

hnco.m, hsqc.m, noesy.m, hcanh.m, hcch_cosy.m, hcch_tocsy.m, hnca.m, hncaco.m, noesyhsqc.m, Built-in_experiments

Version 2.3, authors: Luke Edwards, Ilya Kuprov