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. 2013 Jan 7;8(1):e50759. doi: 10.1371/journal.pone.0050759

Table 2. Best fit parameters for the biphasic activation-inhibition dose-response curves with DAPTa.

ng/mL of pSG5-cDNAwtC99 used to transfect HeLa cells
Data from Fig. 2A a : 0 15 25 61 92 Average
Initial Activity, IA 32 ± 3 41 ± 3 51 ± 5 91 ± 6 119 ± 4 n.a. c
[2σ CI] b [27, 37] [34, 46] [43, 59] [81, 99] [111, 127]
Maximal Activity, MA 217 ± 110 172 ± 90 205 ± 80 180 ± 145 170 ± 95 189
[2σ CI] b [470, 133] [380, 120] [510, 121] [430, 160] [-, -]
Maximal Inhibition, MI -1 ± 0.1 0.33 ± 0.7 -0.2 ± 0.1 1.2 ± 0.2 1.9 ± 0.6 0.5 ± 0.2
[2σ CI] b [-1.75, 1.1] [-1.0, 2.1] [-1.5, 0.9] [-1.36, 0.86] [-2.7, 2.9]
Activation EC50, nM 89 ± 17 71 ± 21 110 ± 34 107 ± 36 178 ± 45 111 ± 41
[2σ CI] b [50, 240] [105, 243] [53, 251] [22, 160] [-, -]
Activation Hill coef. 1.04 ± 0.2 1.08 ± 0.2 1.0 ± 0.1 1.13 ± 0.6 0.92 ± 0.3 1.0 ± 0.1
[2σ CI] b [0.85, 1.35] [0.9, 1.45] [0.9, 1.3] [0.87, 1.28] [0.61, 1.5]
Inhibition IC50, nM 407 ± 34 588 ± 35 524 ± 71 489 ± 62 661 ± 80 534 ± 53
[2σ CI] b [479, 724] [269, 550] [457, 562] [150, 602] [525, 732]
Inhibition Hill’s coef 2 ± 0.3 2.4 ± 0.3 2.2 ± 0.4 2.3 ± 0.5 1.7 ± 0.6 2,1 ± 0.2
[2σ CI] b [1.4, 2.9] [1.6, 3.13] [1.6, 2.9] [1.6, 3.0] [-, -]

The units for all activity measurements are: Aβ 1-40 secreted in pM per 106 cells.

a

the best fit values ± standard error were calculated using nonlinear regression and eqn.1.

b

two sigma confidence intervals as indicated in methods section [34].

c

not applicable, or the corresponding values could not be resolved in the current experiments.

d

no activation is observed when DNA concentration is higher than 250 ng/ml. Thus starting at 250 ng/ml the best fit values ± standard error were calculated using a nonlinear regression and eqn.2.