Figure 8. Synergistic chemical shift changes due to ligand binding.
The 13C ΔΔδ chemical shift differences between the two singly ligated forms of IGPS and the ternary complex is shown versus residue for the Ile, Leu, and Val positions as calculated with equation (1). Residues with a non-additive ΔΔδ value ≥ 1.5 σ from the mean as indicated by the horizontal black lines are mapped onto the IGPS structure in magenta spheres. Acivicin and PRFAR are shown in green and blue sticks, respectively. Not shown are synergistic 1H chemical shift changes, which show similar behavior. See also Supplemental Figures 2 and 3.