FIGURE 3.
Fluorescence titrations of [5F]-SkzL with [Glu]Pg, [Lys]Pg, and FFR-Pm. A, titrations of the fractional change in fluorescence (ΔF/Fo) of 100 nm [5F]-SkzL as a function of total [Glu]Pg concentration ([[Glu]Pg]o) in the absence (●) and presence (○) of 10 mm 6-AHA. B, titrations of 100 nm (●) and 500 nm (Δ) [5F]-SkzL as a function of total [Lys]Pg ([[Lys]Pg]o) concentration in the absence of 6-AHA, and titration of 100 nm [5F]-SkzL with [Lys]Pg in the presence (○) of 10 mm 6-AHA. C, titrations as in B of 100 nm (●) and 500 nm (Δ) [5F]-SkzL, as a function of total FFR-Pm concentration ([FFR-Pm]o) in the absence of 6-AHA, and titration as in B of 100 nm [5F]-SkzL with FFR-Pm in the presence (○) of 10 mm 6-AHA. Solid lines represent the least squares fits of the data by the quadratic binding equation (Equation 1) with the parameters listed in Table 1. Experiments were performed and the data analyzed as described under “Experimental Procedures.”