TABLE 1.

Energy changes of unliganded gating (E₀) and agonist binding (λ) for different loop B mutants

The units are kilocalories per mole. The values are shown in graphical form for αGly147, αTrp149, and αGly153 in Fig. 5. λ is the R/R* affinity ratio (K_d/J_d) for the appropriate agonist. ΔΔG^bind = −0.59ln(λ^mut/λ^wt) and ΔΔG^gate = −0.59ln(E₀^mut/E₀^wt). See Supplemental Tables S1 to S3.

Construct	Ligand	λ (Kd/Jd Ratio)	Net Binding (ΔΔGbind)	Gating (ΔΔGgate)
wtACh	ACh	6587	0.00	0.00
wtcho	Cho	266	0.00	0.00
G147V	ACh	82	2.59	1.73
G147A	ACh	215	2.02	1.40
G147S	ACh	287	1.85	1.12
W149C	ACh	123	2.35	−2.34
W149T	ACh	161	2.19	−1.43
W149A	ACh	202	2.06	−1.22
W149V	ACh	143	2.26	−0.95
W149N	ACh	69	2.69	−0.63
W149M	ACh	79	2.61	0.26
G153K	Cho	151	0.34	−3.14
G153C	Cho	151	0.34	−2.87
G153P	Cho	159	0.31	−2.49
G153A	Cho	175	0.25	−2.41
G153S	Cho	184	0.22	−1.98
T148A	Cho	196	0.18	−0.28
T150A	Cho	161	0.00	−0.64
Y151A	Cho	521	−0.39	1.04
D152A	Cho	339	−0.14	0.13