Table 3

Binding parameters of WT, B2, and B3 stable lines

Saturation Binding
[3H]Yohimbine[125I]PIC
BmaxBmaxKd
−GppNHp+GppNHp−GppNHp+GppNHp
pmol/mg protein nM
WT19  ± 23.2  ± 0.71.5  ± 0.60.8  ± 0.11.4  ± 0.3
B236  ± 31.9  ± 0.51.2  ± 0.51.2  ± 0.32.2  ± 0.7
B334  ± 41.7  ± 0.70.8  ± 0.31.4  ± 0.31.9  ± 0.3

Saturation binding to membranes from CHO-K1 cells expressing WT and mutant α2a-AR was performed in 96-well plates. Membranes were incubated with 1 to 40 nM [3H]yohimbine or 0.1 to 4 nM [125I]PIC for 30 to 45 min at room temperature. [125I]PIC binding was done in the presence or absence of 10 μM GppNHp. Data represent the mean ± S.E. of four or five separate experiments performed in duplicate.