TABLE 1

Comparison of GABA EC50 and Hill slope values of Hco-UNC-49B mutants assembled as heteromeric Hco-UNC-49BC receptors

Fold change values indicate change in GABA EC50 of each mutant normalized to C224A mutant (cysteine-less mutant with wild-type responses, used as template for creation of other loop E mutants).

MutantEC50 ± S.E. (µM)
(Hill Coefficient ± S.E.)nFold Change
C224A32.56 ± 2.29 (1.37 ± 0.11)71
H142C2.70 ± 0.22 (1.44 ± 0.07)a70.1
N143C199.69 ± 22.86 (1.33 ± 0.11)a76.1
S144C133.76 ± 11.96 (1.31 ± 0.07)a74.1
F145C383.53 ± 114.30 (1.40 ± 0.04)711.8
L146C361.39 ± 42.59 (1.30 ± 0.04)a711.1
R147C90.32 ± 6.54 (1.82 ± 0.16)a82.8
I148C19.37 ± 2.62 (1.53 ± 0.13)80.6
D149C39.79 ± 7.11 (2.15 ± 0.27)71.2
S150C54.39 ± 6.95 (1.78 ± 0.13)71.7
D151C36.11 ± 3.25 (1.43 ± 0.08)71.1
G152C54.91 ± 5.01 (1.48 ± 0.06)71.7
T153C122.21 ± 10.01 (1.71 ± 0.08)a63.8
V154C104.05 ± 5.10 (1.51 ± 0.14)a73.2
Y155C111.49 ± 10.68 (1.64 ± 0.09)a73.4
T156C628.48 ± 50.61 (1.71 ± 0.06)a619.3
S157C3683.50 ± 413.66 (1.43 ± 0.09)a8113.1
Q158C35.44 ± 6.63 (1.44 ± 0.10)71.1
R159C3102.33 ± 130.43 (1.53 ± 0.03)a695.3
  • a Values statistically significantly different from C224A (P < 0.001).