All mass spectra were acquired in negative mode on an Orbitrap Fusion Lumos mass spectrometer outfitted with 213 nm UVPD. All spectra were acquired in low pressure mode (also known as intact protein mode). A spray voltage of 1600 V was applied to a fused silica nanoelectrospray emitter (New Objective, 50 µm ID, 30 µm tip) via a stainless-steel tee and platinum electrode. Spectra were recorded from 4 to 8 minutes during desalting at 120k resolution for both MS1 and targeted MS/MS acquisitions.