Fig. 3.

Dissecting Mnx in the gas phase for characterization of quaternary structure. Ion mobility mass spectra of a the isolated 29+ Mnx complex, b CID at 120 V, c SID at a low collision voltage of 40 V, and d SID at a high-collision voltage of 120 V. The color of the spots represents the relative abundance, with the color scale above the figure. Figure 1a was overlaid in a as the light orange trace to better display the single charge state of Mnx that was isolated. When the Mnx complex was activated in the collision cell pressurized with argon in CID b, monomers of MnxE and MnxF were released (around m/z 2000), leaving behind the stripped complex (Mnx complex losing one MnxE or one MnxF, around m/z 9000). Upon activation of SID at 40 V c, the complex dissociates into MnxEF hexamer (mostly E₃F₃) and MnxG (highlighted in red parallelograms), suggesting that the Mnx complex is comprised of a MnxEF hexamer attached to a MnxG monomer. At higher activation energy d, more extensive dissociation of the MnxEF hexamer and Mnx complex into smaller subcomplexes can be observed