Table 2.
Concentration dependence for potentiation by 17β-estradiol
| Combination |
Rmax + 1 |
EC50 |
||||
|---|---|---|---|---|---|---|
| Constructs | No. free WLAGMI | Mean | SE | Mean | SE | N |
| α/β&α4 | 1 | 1.54 | 0.1 | 23.3 | 5.7 | 6 |
| β/αWLAAC&α4 | 1 | 2.04 | 0.1 | 9.4 | 3.1 | 4 |
| β/α&α-M3-β | 2 | 2.96 | 0.2 | 4.5 | 0.6 | 9 |
| αWLAAC&βWLAGMI 8:1 | 2 | 2.97 | 0.2 | 21.1 | 3.5 | 7 |
| α4&β2 8:1 | 3 | 5.00 | 1.0 | 8.0 | 1.1 | 4 |
| β/α&α4 | 3 | 5.81 | 0.3 | 6.3 | 1.0 | 7 |
| α4&βWLAGMI 8:1 | 5 | 7.19 | 0.6 | 19.0 | 3.4 | 4 |
| α4&βM4→C 8:1 | 5 | 13.44 | 1.0 | 39.2 | 13.6 | 4 |
The first column names the constructs injected. The next column lists the number of free C-terminal WLAGMI sequences predicted to be in the assembled receptor. The next columns give the parameters obtained from fitting the concentration–effect relationships (Fig. 7) with the equation R = 1 + Rmax([βEst]/(EC50 + [βEst]), where R is the response ratio, Rmax is the maximal ratio, [βEst] is the concentration of 17β-estradiol, and EC50 is the concentration producing a half-maximal effect. The mean values shown are the means of fits to data from N oocytes injected with that combination. An ANOVA with Bonferroni's correction indicates that the value for EC50 is larger for α4&βM4→C than for all other combinations except for α/β&α, αWLAAC&βWLAGMI, and α4&βWLAGMI. EC50 for α/β&α4 is larger than for β/α&α-M3-β, but no other differences are significant. For values of Rmax, the value for α4&βM4→C is larger than that for all other combinations. Otherwise, values for combinations with one or two free WLAGMI do not differ significantly from each other, nor do values for three or five free WLAGMI. All values for combinations with one or two free WLAGMI were significantly less than all combinations with three or five, except for αWLAAC&βWLAGMI 8:1 whose value for Rmax does not differ significantly from that for α4&β2 8:1.