hcch_tocsy.m

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HCCH-TOCSY pulse sequence from Figure 7.28 of Protein NMR Spectroscopy (2nd edition) 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 proteins and uses PDB labels to select spins that will be affected by otherwise ideal pulses. F1 is 1H, F2 is C, F3 is H.

Syntax

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

Arguments

   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.J_ch        - 1H-13C J-coupling in Hz to be used for 
                            magnetisation transfer, typically 140

   parameters.delta       - coherence transfer evolution delay in
                            seconds, see the pulse sequence diag-
                            ram, typically 1.1e-3

   parameters.lamp        - 1H-13C spin-lock amplitude in Hz, ty-
                            pically 10000

   parameters.sl_tmix     - spin-lock mixing time, typically 2e-3
                            seconds

   parameters.dipsi_dur   - DIPSI period duration, typically 
                            22.5e-3 seconds

   parameters.decouple_f3 - list of spins to be decoupled during
                            the detection period, typically {'13C'}

   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

Below is the output of examples/nmr_proteins/hcch_tocsy_gb1.m example file.

Hcch tocsy gb1.png

Notes

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