Fig. 1.

Representative saturation assays for ¹²⁵I-OVTA binding to OTRs from each of the four species. Cells on 96-well plates were incubated on ice in 50 µl binding medium with the indicated concentrations of ¹²⁵I-OVTA for 3 hours, and specific binding was then quantified. Data are from a single experiment with all four receptors tested side by side in triplicate. Values for this experiment are in good agreement with the average values in the Results and Table 1: humans, B_max = 9.7 fmol/well and K_d = 0.12 nM; macaques, B_max = 6.9 fmol/well and K_d = 0.144 nM; marmosets (R10), B_max = 34 fmol/well and K_d = 0.30 nM; and titi monkeys, B_max = 30 fmol/well and K_d = 0.24 nM.