Table 1.

In vitro activity of the target compounds 6–16, 18c, and 21 against eEF-2K.

compound	R1	R2	R3	IC50 (MM)
7	H	CONH2	cyclopropyl	6.6 ± 0.2
8	Me	CONH2	cyclopropyl	6.1 ± 0.2
6	Et	CONH2	cyclopropyl	0.42 ± 0.01
9	n-Pr	CONH2	cyclopropyl	0.93 ± 0.03
10	CH2-Ph-NO2-p	CONH2	cyclopropyl	>25
11	CH2-Ph-NH2-p	CONH2	cyclopropyl	>25
12	Et	CSNH2	cyclopropyl	>25
13	Et	CO2Et	cyclopropyl	>25
14	Et	CN	cyclopropyl	>25
15	Et	CONH2	Et	1–2
16	Me	CONH2	Me	>25
18c	-	-	-	>25
21	-	-	-	>25

Inhibitor dose response assays were performed with 5 nM recombinant eEF-2K enzyme at various concentrations of the inhibitor, in the presence of 50 μM free Ca²⁺, 200 nM CaM and 10 μM [γ−³²P]ATP, against 150 μM peptide substrate as described under the experimental section. The inhibitor was incubated with eEF-2K for 30 min at 30 °C before initiating the assay with peptide and [γ−³²P]ATP. Kinase activity in each case was determined by calculating the rate of phosphorylation of the peptide (μM/s), and dose-response curves for data conforming to inhibition were fit to equation 1.