“…Complementary information, in particular from structurally sensitive mass spectrometry (MS) based techniques, including native MS, hydrogen deuterium exchange (HDX), ion mobility spectrometry (IMS), crosslinking mass spectrometry (XL-MS), and different forms of ion activation, can help to nd optimal sample conditions, interpret and rene 3D structures, reveal native interactions, and provide information on small ligands and exible protein regions that may have lower resolution in cryo-EM density maps, due to conformational or chemical heterogeneity. 6,[8][9][10][11][12][13][14][15] These studies indicate the potential of establishing a direct link between MS and cryo-EM, to allow for improved correlation between complementary chemical information and high-resolution structures. Electrospray ion-beam deposition (ES-IBD), also known as so landing or preparative mass spectrometry, allows ultra-clean and molecularly pure samples to be prepared on solid surfaces for further analysis.…”