Figure 4.

Binding of ¹²⁵I-labeled MCH to MCHR2. Radioligand binding was performed as described in Materials and Methods. Binding of MCHR1 to ¹²⁵I-labeled MCH was also performed for comparison. Smooth lines are a nonlinear regression fit. MCHR2 bound to MCH with an affinity (K_d = 9.6 ± 0.5 nM) comparable to that of MCHR1 (K_d = 3.1 ± 0.4 nM). (Inset) Scatchard plots. The B_max was about 0.16 nM for both MCHR2 and MCHR1, corresponding to 1.6 nmol/g membrane protein. Data are expressed as mean ± SD (n = 3).