TABLE 4

Effect of mutations on the [MePhe7]NKB-evoked accumulation of [3H]IP. EC50, nH, and Emax values for the NKB-induced formation of [3H]IP in CHO cells expressing transiently the WT and mutated hNK3Rs

The data are mean ± S.E. of eight concentration-response measurements (each performed in duplicate) from four independent transfections. The mutations that affected the potency of [MePhe7]NKB in comparison with WT are shown in bold. Statistical significance was determined using a two-tailed t test.


hNK3R

Position in the 7TMD

[MePhe7]NKB
EC50
EC50 (Mutant)/EC50 (WT)
nH
Relative Emax
nM
WT 1.1 ± 0.0 1.5 ± 0.1 100
V95A 1.42 1.6 ± 0.4 1.5 1.6 ± 0.2 113.5 ± 10.2
V95L 1.42 2.3 ± 0.4 2.1 2.0 ± 0.2 86.5 ± 14.5
V95I/A99S 1.42, 1.46 1.4 ± 0.2 1.3 2.0 ± 0.4 105.1 ± 6.8
M134A 2.53 1.8 ± 0.2 1.6 2.1 ± 0.2 110.0 ± 6.4
N138A 2.57 1020.0 ± 43.9 918.9 *** 1.6 ± 0.3 45.2 ± 13.0
T139A 2.58 2.8 ± 0.8 2.5 1.4 ± 0.1 90.2 ± 32.2
V95L/T139A 1.42, 2.58 5.2 ± 0.2 4.7 1.6 ± 0.1 120.3 ± 6.0
N142A 2.61 16.0 ± 0.8 14.4 *** 1.1 ± 0.1 66.1 ± 17.9
V169M 3.36 4.6 ± 1.5 4.1 1.0 ± 0.2 104.0 ± 13.4
L232A 45.49 5.9 ± 0.4 5.3 *** 1.1 ± 0.1 99.8 ± 4.0
Y315F 6.51 5.8 ± 0.9 5.2 *** 0.9 ± 0.2 71.8 ± 15.2
S341A 7.38 2.8 ± 0.6 2.5 1.9 ± 0.3 106.5 ± 11.4
F342A 7.39 130.0 ± 11.0 117.1 *** 1.2 ± 0.3 80.5 ± 5.7
F342M 7.39 10.0 ± 1.4 9.0 *** 0.9 ± 0.1 72.9 ± 13.9
S341I/F342M 7.38, 7.39 10.0 ± 2.2 9.0 *** 0.8 ± 0.1 102.9 ± 12.1
M346A 7.43 24.0 ± 2.9 21.6 *** 0.9 ± 0.2 113.0 ± 4.3
S348A
7.45
3.7 ± 1.0
3.3
1.2 ± 0.1
103.3 ± 7.8
  • *** P < 0.001.