As isCA becomes more energetic, the observed dissociation pathways change to favor monomer formation. An interesting region of the plot is between 80 -110 V. In this region the monomer and dimer signals increase while the trimer and tetramer signals gradually decrease, and the residual pentamer signal dramatically decreases. These trends suggest post-SID secondary fragmentation, likely due to excess energy from isCA. As the ions undergo isCA, an amount of translational energy is converted to internal energy, leaving the ions internally hot. When these hot ions undergo SID, the sudden energy deposition results in native-like SID (dimer/trimer and monomer/tetramer formation), but the extra energy from isCA then drives the oligomeric product ions to dissociate further: trimer to monomer/dimer and tetramer to dimer/dimer and monomer/trimer. Since these secondary dissociation events have several pathways to monomer and dimer we see the commensurate rise in those respective signals. The trimer signal decreases overall since a portion of the initial trimer population dissociates to monomer/dimer while a new trimer population emerges since the initial tetramer product can form trimer as part of its secondary dissociation. This region shows how high amounts of isCA can have a dramatic effect on downstream tandem MS analyses, which would not have been apparent without carefully scanning isCA at a fixed SID potential. The end of this region coincides with the initial drift time shift in the overlayed CIx plot in Figure , which suggests that quaternary structure rearrangement has been minimal and that increased internal energy from isCA is driving the shift in SID trends. At isCA voltages above 110 V, the monomer product becomes dominant, which aligns with the dramatic drift time shift in the CIx plot which indicates a collapsing quaternary structure.