Table 5 Experimentally determined pK values of α-MSH for MC4 receptor mutants. Shown is the average pK ± SD determined in radioligand binding competition using [125I]NDP-MSH as radioligand. (The numbers of independent replicates are in brackets). The significance, p, is calculated using nonparametric Wilcoxon Rank Sum test [29] (see Methods for details), when compared with the wild-type MC4 receptor.
Name | pKi (log(nM)) ± SD (Repeats) | p |
|---|---|---|
MC4 | 5.73 ± 0.32 (22) | - |
Q43E/P48D | 6.19 ± 0.14 (11) | 1.3E-4 |
I66V | 5.98 ± 0.26 (12) | 9.8E-3 |
A89S | 5.69 ± 0.14 (14) | 6.4E-1 |
I102A | 5.56 ± 0.30 (12) | 1.8E-1 |
I129T | 6.02 ± 0.15 (11) | 4.1E-3 |
A135S | 6.00 ± 0.15 (10) | 1.0E-2 |
L141G | 6.08 ± 0.15 (9) | 3.0E-3 |
I251L | 5.71 ± 0.36 (10) | 7.0E-1 |
Y268I | 5.88 ± 0.20 (14) | 3.8E-2 |
Q43E/P48D/I66V | 6.30 ± 0.17 (11) | 1.5E-5 |
I66V/L141G | 6.03 ± 0.20 (11) | 4.6E-3 |
I129T/A135S | 6.47 ± 0.51 (10) | 2.3E-5 |
L141G/Y268I | 6.01 ± 0.27 (12) | 9.8E-3 |
Q43E/P48D/I66V/I129T/A135S | 6.52 ± 0.17 (11) | 1.4E-7 |
Q43E/P48D/I66V/I129T/A135S/L141G/Y286I | 6.49 ± 0.31 (9) | 1.8E-5 |
N240G/M241L/I245V | 6.10 ± 0.10 (5) | 1.1E-2 |
V253I/V255F/V256L | 6.19 ± 0.16 (5) | 4.3E-3 |
IL3 | 6.72 ± 0.14 (5) | 1.7E-5 |
S4 | 6.98 ± 0.17 (5) | 1.7E-5 |