Topic: 1 Dalton mass shift in z peptides


I find that the calculated mass for z peptide is one dalton lower than the actual mass and the masses computed by protein prospector. I guess this is due to the electron transfer in the ETD. Is there a workaround for that or would one have to fix that in the source?

Thanks for the great software,



Re: 1 Dalton mass shift in z peptides

Hi Johannes,
all the fragments definitions are according to Mascot. To change it, unfortunately, you would have to modify the source code.