TABLE 4 

Inhibition of WT-RGS GAP activity at hGαi1 (R178M, A326S)

Biochemical characterization of RGS inhibitors for their ability to disrupt the GAP activity of WT-RGS RH domains using phosphate detection assay to monitor Gα GTPase activity using hGαi1 (R178M, A326S) rapid turnover mutant. Data represent the IC50 with the 95% CI in parentheses from n = 3 independent experiments, each with duplicate wells. Concentration response curves are shown in Fig. 3. NC indicates that an IC50 value was not calculable owing to a complete lack of inhibition.

RGSIC50, μM (95% CI)
CCG-63808CCG-55919CCG-4986CCG-50014CCG-63802UI-1590
17.2 (5.7–9.1)1.9 (1.5–2.4)64 (43 to >100)0.16 (0.14–0.19)15 (12–18)1.8 (1.3–2.5)
43.9 (2.4–6.0)0.54 (0.41–0.71)3.6 (2.6–4.9)0.22 (0.18–0.27)5.3 (4.3–6.5)1.4 (1.2–1.7)
520 (15–28)>100NC17 (14–22)34 (25–48)27 (16–58)
822 (16–30)>100NC22 (17–28)38 (28–52)39 (21 to >100)
1619 (15–25)>100>1006.8 (5.2–8.9)32 (25–40)40 (25–74)
1731 (21–46)NCNC55 (35 to >100)49 (32–84)>100