Problem with pick and assign

I am using version 3 on a new set of data, and pick and assign (+signal assign) worked normally for about 2/3 of my data, but the final third of peaks picked in my gNhqc are not working properly. When I click on the line of these peaks in the pick and assign module, it will not navigate to the correct nitrogen plane in the 3D spectra (even though it will automatically navigate to the correct N plane when I click on other peaks). Then if I try to click “restricted pick” or “assign selected” on these signals, it gives me an error saying " Cannot pick peaks; check selected spectrumDisplay, possibly missing axis-codes or selected nmrResidue has no matching axis-codes". It will also not navigate to the correct N plane for these peaks when using the backbone assign module. I can use the atom assigner though and manually pick peaks in the 3D spectrum. Any help would be appreciated!

I wonder if this could be an issue with aliased peaks. Do your 2D and 3D spectra have same sweep width in the Nitrogen dimension? If it is smaller in the 3D, then the navigation will have to adjust.

Best thing is to open the Spectrum Properties for your 3D (double click on the spectrum in the sidebar) and check if the aliased region includes the full Nitrogen sweep width of your 2D.

If not, then simply select Aliasing values so that they are shown.

Other things to try when peaks are not being picked:

  • increase the number of planes being shown (change the number next to your Z-axis navigation from 1 to 3, for example).
  • check that your Axis Codes match (I can’t remember whether only the first letter has to match or the full code), but probably best if your spectra all have N and H or Nh and Hn for the Nitrogen and Proton axes, not a mix of the two. Did you perhaps change some part way through?