TABLE 2

Affinities of ligands for the allosteric site, estimated in terms of Scheme 1

The data represented in Fig. 5 were analyzed simultaneously in terms of Scheme 1 to obtain the parametric values listed in the table. Values of K_L and m_L (L ≡ A, B, or C in eq. 10) were assigned to each ligand as follows: in the case of NMS, oxotremorine-M, and gallamine, single values of each parameter were common to all of the relevant data; in the case of obidoxime, a single value of m_L was common to all of the data, and separate values of K_L were assigned to data acquired with obidoxime taken alone and in the presence of 10 mM NMS, 32 mM oxotremorine-M, or 1 mM gallamine. The latter values are listed in the table under K_Obi, where the value of K_L for obidoxime alone is reprinted in brackets for the purpose of comparison. A separate value of k_P/k_o was assigned to the data from each experiment, and the mean is 1.01 ± 0.01 (n = 36). The value of m_L for gallamine was fixed at 1 during the fitting process, as described in the text. The weighted sum of squares was not increased appreciably when the affinity of obidoxime was estimated as 1 parameter rather than 4 (p = 0.089), and the resulting value of K_L is −1.73 ± 0.08.