Figure 3

(a) Snapshots of IgG1 molecules generated by homology modeling of 1HZH, 5DK3, 6GFE, 1IGT, 1IGY crystal structures, all aligned to the Fc region of 1HZH. The reference 1HZH structure is shown in the background for comparison. The conformation of the AlphaFold structure post 1000 ns of relaxation is also shown. (b) Spatial occupancy density plots for each structure, computed from two independent 500 ns trajectories, show \({x}_{4}\), \({y}_{4}\), and \({z}_{4}\), the x, y, and z positions of bead 4, vs \({\theta }_{123}\). The point clouds associated with each group was constructed from around 5e4 observations. The conformational states accessed by each of the structures show minimal overlap in Cartesian space, pointing to the presence of locally minimum states in both IgG1 and IgG4 structures. (c) The spatial separation between the conformational states accessed by the various structures is quantified by the Kantorovich–Wasserstein distance metric, \({d}_{KW}\). For reference, \({d}_{KW}=0\) for two identical clouds of points, and \({d}_{KW}=2.6\) for two normally distributed clouds of points centered around (0,0,0) and (2,0,0), respectively.