Make assignments of CA and CB in triple resonance spectra. (HNCA, HNCACB etc)
Then there are different roads:
- If you've measured (H)CCH type spectra, you can use CA/CB and CB/CA pairs in SystemScope to find HA and HB, then use HB/CB to look for CG.
- If you have measured (H)CCH-TOCSY, you can also start from HA/CA anchor in SystemScope to find all the remaining sidechain C shifts.
- Or, you can measure HNHA to obtain HA. With the HA/CA anchor, in SystemScope you can start using a H(C)CH-COSY and/or H(C)CH-TOCSY, or possibly the 13C-resolved NOESY, to work your way into the sidechains.
- Alternatively, you can measure H(CCCO)NH and (H)C(CCO)NH spectra and use the HN/N anchors in StripScope to pick the TOCSY towers of the previous residue based on the characteristic chemical shifts. Once all strips are picked, copy the projected spins to origin systems using CopyProjectedSpinsToOriginSystem.lua and check positions in the 13C-HSQC.
If you want a slightly longer version of these strategies, have a look at the CARA wiki page on heteronuclear sidechain assignment