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. Author manuscript; available in PMC: 2018 Feb 20.
Published in final edited form as: ACS Comb Sci. 2017 Sep 29;19(11):694–701. doi: 10.1021/acscombsci.7b00109

Figure 2.

Figure 2

Spectra with incomplete b/y-fragmentation ladders can be unambiguously assigned using the AMS principle. Displayed are merged, preprocessed CID and HCD spectra for 491.243 Da/e precursor ions. The first candidate sequence does not match the library design pattern due to the fact that the pair of b3/y7 ions is not observed in the spectrum, and consequently, an unreliable assignment is made. The molecular weight difference of 186.064 Da between the observed fragment ions corresponds to four different dipeptides (Gly-Glu, Glu-Gly, Ala-Asp, and Asp-Ala), but only one of them (Asp-Ala) matches the parent design, which makes an unambiguous assignment possible. ss1: monomer subset 1, ss2: monomer subset 2, cr: constant region.