Figure 6.

Static spectra for the reactions of various MVC forms of α₂β₂ with L-His (eq 5) in the absence (A) and presence (B) of F9. MVC forms: Na⁺ (black), Cs⁺ (red), MVC-free (green), and NH₄⁺ (yellow). (C) Binding isotherms measured at 470 nm for the titration of F9 into a premixed solution of α₂β₂, L-His and the Cs⁺ (black circles) or Na⁺ (open triangles). Each line is the least squares best fit of the data. Final Concentrations: 100 mM L-His, 50 mM MVC, and when present 200 µM F9; 10 mM α₂β₂ in (A) and (C), and 20 µM α₂β₂ in (B).