Figure 4.

Inhibition of [³H]-granisetron binding to wildtype and mutant receptors by analog 1 and analog 2. Competition binding assays were performed as described in Materials and Methods. Each point represents a mean ± SE of n> 4 experiments. IC₅₀ values were determined from the data and a K_i value calculated using the Cheng-Prusoff equation. K_i values for inhibition on each mutant are shown in Table 1 for all three compounds. A. Wildtype B. W89F C. W89Y D. R91A E. Y142A F. Y152A