hcch_cosy.m
HCCH-COSY pulse sequence from Figure 7.26a 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.
Syntax
fid=hcch_cosy(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.J_cc - 13C-13C J-coupling to be used for mag-
netisation transfer, typically 35 Hz
parameters.J_ch - 1H-13C J-coupling to be used for mag-
netisation transfer, typically 140 Hz
parameters.delta - evolution delay, see the pulse sequence
diagram, typically 1.1e-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 - a structure with four fields: fid.pos_pos, fid.pos_neg,
fid.neg_pos, fid.neg_neg that are used in the subsequ-
ent States quadrature processing
Examples
Below is the output of examples/nmr_proteins/hcch_cosy_gb1.m example file.
Notes
- Spin labels must be set to PDB atom IDs ('CA', 'HA', etc.) in sys.labels for this sequence to work properly.
- F1 is 1H, F2 is C, F3 is H.
See also
hcanh.m, hnca.m, hncaco.m, hnco.m, hncoca.m, noesyhsqc.m, Built-in_experiments
Version 2.5, authors: Matt Walker, Ilya Kuprov
