Cone isCA -ECD experiments were conducted at two different cone settings, either 20 or 160 V, followed by quadrupole isolation of the same charge states as were selected for the isCA -SID experiments, then by IM separation, and finally by electron capture in the ExD device located in the pre-transfer guide after IM. Because ECD product ions tend to remain "stuck" (non-covalently bound) within native-like proteins/complexes due to non-covalent interactions, post-ECD activation (transfer collision energy (TCE)) was used after electron capture to liberate the fragments. Typical Transfer CE voltages ranged from 60 -130 V. All ECD spectra were processed using ExDViewer v4.5.8 (eMSion, an Agilent company), with the default deconvolution and peak picking settings and a mass tolerance of 20 ppm for product ion matching.