Table 1

Dissociation constant (Kd) and stoichiometry of amobarbital binding to nAChRs in the desensitized and resting state.

AChR StateKdStoichiometry Binding Sites/nAChRr2
Resting3.7  ± 0.70.89  ± 0.140.86
Desensitized930  ± 38011  ± 50.25

The Kd values in the nAChR resting state were obtained from the negative reciprocal of the slope of Fig. 1B, according to eq. 1. The values in the desensitized state were estimated from Fig. 1C. The number of amobarbital binding sites per nAChR in the resting state was obtained from the x-intersect of Fig. 1B, according to eq. 1, and considering the concentration of receptor employed (0.3 μM). The stoichiometry in the desensitized state was estimated from Fig. 1C. Values are reported as mean ± S.D. r2 expresses goodness of the fit.