Hello,
It sounds like you should be setting the min and max aliased freq of the
3D experiments to (at least) match the fundamental region of the HSQC. To
set these go to the Experiments --> Edit Spectra dialog and select the
Referencing tab. The min and max aliased freqs are the last two columns.
If they are blank (the default) then this means the boundary is the
fundamental region of that spectrum.
When these are set you then want to pick the peaks in the 3D at their
actual (unaliased, true) ppm value. If you have already picked peaks in
the 3D at the aliased (incorrect) position then you can change this in the
Peaks --> Peak Lists dialog in the Peak Table tab. If you select a peak
then click on the Unaliase button at the bottom. You can also get at this
by selecting the peak in the spectrum window and right mouse click menu
item Peak --> Unalias peak.
Hope this makes sense.
Wayne
On Fri, 24 Apr 2009, Beate Bersch wrote:
> Hi
> We are currently trying to work through an ensemble of 3D backbone
> assignment spectra that have been acquired with a reduced spectral width in
> the N15 dimension (gain in resolution/experimental time) and several peaks
> are refolded (type States).
> We have a full HSQC spectrum that we have used as a reference (in order to
> obtain the correct N15 shifts) and also a reduced one. We could not find a
> way to move between the (un)folded peaks in the reference spectrum and the
> 3D spectra and also to add the 13C frequency from a 3D spectrum to a
> (refolded) spin system (different N15 shifts). One way to work around would
> be to use the folded HSQC spectrum as a reference and to manually correct
> the N15 shifts at the end - but I am sure that there are more elegant ways
> to handle this problem.
> Thank you for all your time and efforts
> Sincerely
>
> Beate
>
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