HA/HB assignment

I do manual assignment of HA and HB.
For some amino acide I have 2 HB chemical shift.
But I feel like that ccpnrm V3 doesn`t take into account the 2 chemical shift assignment; because when I check my peaks in the other spectra there is only one marker which is the average of the two peak that I had already assigned with assigning peak module.
Is it possible to force ccpnmr V3 to take into account 2 different values of HB ?
Thank you in advance for your answer.

Hi Séraphine,

I wonder if this is an issue with atom naming. If you have an amino acid such as Ser which has two HB atoms, then you could have three different scenarios:
1) both atoms have the same chemical shift. In this case you should label the atom as HB%
2) the atoms have different chemical shifts, but you don`t know which one is which (i.e. you don`t have stereospecific assignment). In this case you should label the atoms as HBx and HBy
3) the atoms have different chemical shifts and you know which one is HB2 and which is HB3 (following the IUPAC stereospecific atom naming in protein structures). In this case you can label them HB2 and HB3. I would usually anticipate this case begin very rare. It is usually only for Val/Leu methyls that people do special experiments to be able to make stereospecific assignments. But a structure calculation programme might be able to determine the stereospecific assignment for you, too.

I wonder if your problem is that in scenario 2 you are simply labelling both your peaks as HB. The peaks then have the same label, and the chemical shifts are always averaged across all peaks that have the same peak label.

For more information on atom naming see https://www.ccpn.ac.uk/manual/v3/NEFAtomNames.html

Hope this helps.
Best wishes,

Thank you very much for this answer.
Indeed, I noted the proton as HB because I can`t find any other option. thank to your link i saw the possible names, and I searched a little bit more. I saw that in NmrAtomAssigner I was in backbone mode. so I changed to all and I found everything I needed to assign my HA and HB correctly.
Thanks for the advice