C alpha E.COSY TROSY hHNCO

Ref.:
A.Meissner, and O.W.Sørensen J.Magn.Reson. 143, 431-434 (2000). (3hJ Coupling between C and HN across Hydrogen Bonds in Proteins)
3D C E.COSY TROSY hHNCO pulse sequence for measurement of 3hJ(HN,C) coupling constants across hydrogen bonds in proteins.
Delays:  = (2JN,H)-1; T = n(1JN,CO)-1, n = 1,2; T' = T - (duration of water-selective /2 pulse);  = gradient delay.
Phases for Varian Unity Inova:  = -y; {I = y; S = y} (echo) and {I = -y; S = -y} (antiecho).
Phases for Bruker DRX:  = y; {I = -y; S = -y} (echo) and {I = y; S = y} (antiecho).
Gradient ratios: -4.375(G1), 1.875(G2), 1.250(G3) for echo; -5.000(G1), 1.250(G2), 1.875(G3) for antiecho.
 

Varian:

For measurement of 3hJ(HN,C) set flag
select = 'a' for TROSY line

decca = 'n'

Set dof to the middle of the CO region. For adjustment of other parameters, please refer to the comments in the header of the pulse sequence.

To generate the selective pulse shapes, copy water_sc.inp, ib_co_onr.inp to your $HOME/vnmrsys/shapelib directory, adjust ref_pwr and ref_pw90 according to your proton (water_sc.inp) and carbon (ib_co_onr.inp) pulse calibration. Type the command: Pbox -f >filename<.inp for each of the files to generate the shapes.

An output like
>>> Set pulse width to 1.0000 ms <<<
>>> Set pulse power to 21 dB <<<
appears.

Remember to adjust the parameters according to the output.
 
 

Program tested on: Varian Unity Inova, Vnmr6.1B, Pbox6.1C, Solaris7

Content
Pulse sequence:   hbond_hc.c
Parameters:       hbond_ha.par
Pbox input files: water_sc.inp
                  ib_co_onr.inp

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Bruker:

not yet available
 
Document: Ca E.COSY TROSY (index.shtml)
Last modified: 2005-12-19