Apply selected neutral losses to the precursor #1
Description
Example spectrum in PeptideAtlas:
https://db.systemsbiology.net/dev2/sbeams/cgi/PeptideAtlas/ShowObservedSpectrum?atlas_build_id=442&spectrum_identification_id=1716849097&peptide=n[145]MTQSPSSLSASVGDR&assumed_charge=2
Look at Eric's annotation (water loss on precursor):
1522.7034 22.0 y15/-8.7