  Among many techniques of modern mass spectrometry, the top down methods are
becoming continuously more popular in the overall strive to describe the
proteome. These techniques are based on fragmentation of ions inside mass
spectrometers instead of being proteolytically digested. In some of these
techniques, the fragmentation is induced by electron transfer. It can trigger
several concurring reactions: electron transfer dissociation, electron transfer
without dissociation, and proton transfer reaction. The evaluation of the
extent of these reactions is important for the proper understanding of the
functioning of the instrument and, what is even more important, to know if it
can be used to reveal important structural information. We present a workflow
for assigning peaks and interpreting the results of electron transfer driven
reactions. We also present software written in Python and available under GNU
v3 license.
