Fig. 5: I88 side chain conformation is ion dependent.

a Strips for I88 Cδ1 from 3D CCH NOESY experiments collected in 600 mM Na⁺ (red, ¹H ppm = 0.567) and 100 mM K⁺ (black, ¹H ppm = 0.576). b Distances from I88 Cδ1 to V64 Cγ2 and V91 Cγ1 in the ‘up’ (black) and ‘down’ (red) conformations. NOESY data collected in K⁺ is consistent with the ‘up’ conformation, while the data collected in Na⁺ is more consistent with the ‘down’ conformation.