Figure 3.
Distribution of intra-chain domain-orientation angles between CH2 and CH3 for the ensemble models of IgG1-Fc and various crystal structures of IgG1-Fc. The angles between the CH2 and CH3 domains of chain A and chain B were plotted on the X axis and Y axis, respectively, for the ensemble models derived from MD simulations starting from the initial structures based on (a) asymmetric crystal structure (3AVE) supplemented with the crystallographically unobserved N- and C-terminal segments, (b) symmetric crystal structure (5IW3) supplemented with crystallographically unobserved N- and C-terminal segments, (c) crystallographically observed parts of 3AVE, and (d) 5WI3 supplemented with the crystallographically unobserved N- and C-terminal segments with deletion of the N-glycans. In A, B, and C, the N-glycans of each initial structure were modeled to have the core fucose residue and the terminal galactose residue of the α1-6Man branch. The angles observed in the crystal structures are represented as circles for uncomplexed Fc structures (red, the starting structures used for the corresponding MD simulations; black, Fc with native N-glycans; white, Fc with enzymatically trimmed N-glycans; yellow, aglycosylated Fc), rectangles for complexed Fc structures (white, complex with sFcγRs; green, complex with other ligands).