. Author manuscript; available in PMC: 2015 Mar 20.

Published in final edited form as: Mol Pharmacol. 2003 May;63(5):1021–1031. doi: 10.1124/mol.63.5.1021

TABLE 1.

The competition of binding of a radiolabeled agonist [¹²⁵I]I-AB-MECA to WT and mutant human A₃ receptors by competitive ligands and allosteric modulators

	IC₅₀			K _i			K_d
	HMA	DU124183	VUF5455	Cl-IB-MECA	MRS1220	PSB-11	[¹²⁵I]I-AB-MECA
		μM			nM		nM
WT	1.8 ± 0.2	1.2 ± 0.3	2.8 ± 0.4	2.3 ± 0.62	1.6 ± 0.3	2.8 ± 0.9	1.2 ± 0.2
N30A^1.50	9.7 ± 2.2	6.2 ± 1.1	29 ± 11	226 ± 36	2761 ± 853	270 ± 68	9.8 ± 2.3
D58N^2.50	1.9 ± 0.4	1.3 ± 0.1	2.9 ± 1.1	4.6 ± 0.7	1.2 ± 0.5	2.5 ± 0.3	2.1 ± 0.3
T94A^3.36	2.2 ± 0.3	2.7 ± 0.7	6.4 ± 0.9	11.2 ± 2.5	10.1 ± 3.7	33 ± 12	4.3 ± 0.7
H95A^3.37	48 ± 23	36 ± 18	28 ± 12	60 ± 15^a	976 ± 119^a	1120 ± 270	5.7 ± 1.2^a
D107N^3.49	2.0 ± 0.3	2.8 ± 0.4	9.7 ± 1.0	1.8 ± 0.4	9.2 ± 0.7	27 ± 8	0.55 ± 0.13
K152A^EL2	1.9 ± 0.3	3.2 ± 0.5	23 ± 71.	7 ± 0.6^a	5.4 ± 0.7^a	26 ± 7	3.7 ± 1.4^a
F182A^5.43	2.4 ± 0.6	29.6 ± 7.3	2.9 ± 0.5	5.2 ± 0.8	2.7 ± 1.8	9.2 ± 2.1	3.5 ± 0.7
W243A^6.48	0.44 ± 0.07	3.6 ± 0.3	17 ± 52	2.9 ± 0.5^a	45 ± 13^a	44 ± 11	1.1 ± 0.3^a
L244A^6.49	1.9 ± 0.3	2.1 ± 0.2	4.6 ± 0.5	2.5 ± 0.7^a	0.63 ± 0.14^a	2.3 ± 0.6	0.85 ± 0.11^a
S247A^6.52	0.9 ± 0.3	1.0 ± 0.2	3.9 ± 1.2	2.2 ± 0.2^a	3.1 ± 1.4^a	2.9 ± 0.3	1.7 ± 0.3^a
N274A^7.45	1.9 ± 0.3	2.4 ± 0.4	5.7 ± 1.0	7.0 ± 2.1	870 ± 220	144 ± 27	4.6 ± 1.3

Data from Gao et al. (2002a).

Results were expressed as means ± S.E. from three independent experiments. M177A^5.38, VITSA^5.39, S271A^7.42, and H272A^7.43 mutant receptors lost high-affinity binding of both agonist ([¹²⁵I]I-AB-MECA, 0.5 nM) and antagonist ([³H]PSB-11, 8 nM).