TABLE 1.

Characteristics of cAMP analogues as tested on isolated PDE10 GAF domains as FRET construct

Half-maximally effective concentrations (EC₅₀) of different cAMP analogues to elicit conformational changes of the PDE10 GAF domains are given. Conformational changes of the GAF domains were determined by FRET measurements in vitro as outlined under “Experimental Procedures.” EC₅₀ values are from at least three independent determinations performed in duplicate; 95% confidence intervals are given in parentheses. —, no FRET change detectable at 100 μm. Full chemical names and structures of the analogues are listed in supplemental Table 1 and supplemental Fig. 1.

Analogue	EC50
	μm
cAMP	0.28 (0.14–0.58)
1-NO-cAMP	17 (11–28)
2-DMA-cAMP	>100
Rp-cAMPS	40 (25–64)
Sp-cAMPS	40 (23–71)
8-N3-cAMP	—
2-Aza-ϵ-cAMP	—
2-AHA-cAMP	>100
Ara-cAMP	4.0 (2.0–7.7)
8-N3-ϵ-cAMP	—
2′-NH2-cAMP	37 (27–50)
8-Br-cAMP	54 (32–93)
6-Bn-cAMP	—
6-Bnz-cAMP	>100
8-BT-cAMP	—
cCMP	—
6-Cl-cPuMP	10 (6–18)
8-Cl-cAMP	41 (30–57)
8-CPT-cAMP	—
2-Cl-cAMP	1.1 (0.6–2.0)
2-Cl-MA-cAMP	—
2′-dcAMP	0.95 (0.51–1.77)
7-CH-cAMP	0.59 (0.22–1.5)
2′-F-cAMP	—
ϵ-cAMP	5.5 (3.4–9.0)
8-OH-cAMP	—
8-MA-cAMP	—
6-MB-cAMP	10 (5–20)
2′-O-Me-cAMP	—
6-DMA-cPuMP	—
6-MA-cPuMP	—
6-Phe-cAMP	—
cTMP	—
cUMP	>100