Table 1. 5-HT and mCPBG EC50 Values and Hill Coefficients for N128 and E129 Mutant Receptorsa.
| receptor | 5-HT pEC50 | 5-HT EC50 (µM) | nH | mCPBG pEC50 | mCPBG EC50 (µM) | nH |
|---|---|---|---|---|---|---|
| WT | 5.93 ± 0.01 | 1.2 | 2.54 ± 0.15 | 6.33 ± 0.02 | 0.47 | 2.03 ± 0.23 |
| N128A | 5.44 ± 0.03 | 3.6 | 1.34 ± 0.13b | 5.95 ± 0.02 | 1.1 | 1.33 ± 0.08 |
| N128D | 5.51 ± 0.01 | 3.1 | 1.63 ± 0.08b | 6.56 ± 0.03 | 0.27 | 1.54 ± 0.15 |
| N128E | 5.68 ± 0.04 | 2.1 | 1.48 ± 0.18b | 6.56 ± 0.03 | 0.28 | 1.81 ± 0.019 |
| N128Q | 4.64 ± 0.03b | 23 | 2.11 ± 0.29 | 5.52 ± 0.18b | 3.0 | 2.41 ± 0.16 |
| N128R | SR | SR | SR | 5.14 ± 0.02b | 7.3 | 1.93 ± 0.16 |
| N128K | 4.47 ± 0.03b | 34 | 2.13 ± 0.38 | 5.41 ± 0.03b | 3.9 | 1.43 ± 0.16 |
| N128V | 7.04 ± 0.02b | 0.091 | 3.18 ± 0.60 | 7.13 ± 0.02b | 0.074 | 5.07 ± 0.85b |
| N128-Akp | 5.33 ± 0.01b | 4.6 | 1.49 ± 0.06b | ND | ND | ND |
| N128-Nha | SR | SR | SR | 5.55 ± 0.02b | 2.8 | 2.18 ± 0.23 |
| E129A | NR | NR | NR | NR | NR | NR |
| E129D | 5.73 ± 0.03 | 1.9 | 1.81 ± 0.16b | 6.60 ± 0.10 | 0.25 | 1.19 ± 0.31 |
| E129G | NR | NR | NR | NR | NR | NR |
| E129H | 4.85 ± 0.09b | 14 | 1.07 ± 0.24b | 6.43 ± 0.04 | 0.37 | 1.63 ± 0.20 |
| E129K | NR | NR | NR | NR | NR | NR |
| E129N | 4.25 ± 0.02b | 56 | 1.17 ± 0.07b | 6.21 ± 0.05 | 0.62 | 1.25 ± 0.19 |
| E129Q | 3.93 ± 0.01b | 120 | 1.55 ± 0.07b | NR | NR | NR |
| E129-Nha | 5.45 ± 0.04 | 3.5 | 1.18 ± 0.12b | 6.25 ± 0.07 | 0.56 | 1.91 ± 0.60 |
a
Data are means ± the standard error of the mean (n = 3−16). NR indicates no response. SR indicates small (<100 nA) responses. ND indicates not determined.
b
Significant difference p < 0.05 and for pEC50 values >3-fold different from that of WT.