. Author manuscript; available in PMC: 2011 Nov 1.

Published in final edited form as: Drug Dev Res. 2010 Nov 1;71(7):404–411. doi: 10.1002/ddr.20388

TABLE 2.

Effects of Truncating the Alkyl Side Chain of Dimethylpentyl Δ⁸-THC on Ligand Binding Affinity to Cannabinoid Receptors With Mutations in Positions 268–271 in EC2


	K_i (nM)
Receptor	CP55940^a	HU-210^a	JWH061	JWH179
WT	24.8 (14.6–42.3)	3.7 (2.1–6.5)	29.9 (18.5–48.3)	7.3 (5.4–9.8)
F268W	8132 (5793–11421)^*	1672 (757.9–3689)^*	3459 (2619–4568)^*	1112 (922–1342)^*
[WT:F268W]^b	[1:328]	[1:452]	[1:116]	[1:152]
P269A	2081 (1256–3446)^*	22.6 (10.3–49.5)^*	1728 (1414–2111)^*	798 (620–1027)^*
WT:P269A^b	[1:84]	[1:6]	[1:58]	[1:109]
H270A	188 (152–232)^*	13.8 (9.4–20.1)^*	373 (226–618)^*	90.0 (79.3–102)^*
WT:H270A^b	[1:8]	[1:4]	[1:12]	[1:12]
I271A	3306 (1422–7686)^*	310 (117–822)^*	773 (623–958)^*	194 (158–240)^*
WT:I271A^b	[1:133]	[1:84]	[1:26]	[1:27]

Data are the median and corresponding 95% confidence limits of three independent experiments performed in duplicate. K_i values for each ligand were determined using 4 nM [³H]SR141716A.

Statistically significant differences from wild-type (P<0.05) using analysis of variance followed by Dunn's post hoc test.

K_i values from Ahn et al. [2009], except for H270A, which was obtained here.

Values represent the K_i ratio for WT to EC2 mutant receptors for the specified compound.