3D peak picking (1)

The next step in our assignment strategy is to use the 2D 15N-HSQC peaks to navigate in the 3D spectra, pick the peaks at the corresponding HN frequency, and assign them to the same root resonances as the 2D 15N-HSQC peak:

• • Click on a peak

  • Mark it with 'm'

• R: Navigate: 1H-15N in HCN

The CBCAcoNH spectrum is now shown at the HN position from the HSQC, e.g.:

Now pick the 2 peaks in the CBCAcoNH as if it was a 2D spectrum, by holding down 'CTRL' + 'SHIFT' and drawing a rectangular box. Select one of the peaks, and assign its 1H and 15N frequencies to the root resonances using Assignment: Assignment Panel. (R: Assign: Assign CBCAcoNH...). Note that now there is a third dimension added, 13C, for the CBCAcoNH. Likewise, the second peak can be assigned, by selecting it and assigning it:

Alternatively, in the case of multiple peaks, it is most convenient to assign 1 peak, then select all the peaks belonging to the same spin system, and use R:Assign:Propagate assignments. This will assign all peaks in 1 step to the same root frequencies. Try this in the same window using the HNCACB.

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