Table 3.
Kinetic and thermodynamic parameters of bupropion binding to Torpedo AChRs in different conformational states determined by non-linear chromatography studies.
| Parameter | Condition | |
|---|---|---|
| α-BTx treated column1 | Epibatidine treated column2 | |
| koff (s−1) | 0.44 ± 0.01 | 0.50 ± 0.02 |
| kon (s−1µM−1) | 0.16 ± 0.01 | 0.15 ± 0.02 |
| Ka (µM−1) | 0.35 ± 0.03 | 0.29 ± 0.04 |
| ΔG20 (kJ mol−1) | −31.1 ± 0.2 | −30.6 ± 0.3 |
The CMAC-Torpedo AChR column was pretreated with either α-BTx1 (the AChR is mainly in the resting state) or epibatidine2 (the AChR is mainly in the desensitized state).
The koff and Ka values were empirically determined from Fig. 4 and Fig. 5, respectively, according to eq. 6 and eq. 7, respectively, whereas the kon values were calculated as kon = koff. Ka.
The ΔG values were calculated using eq. 5 at the experimental temperature T = 293K.