Figure 4.

DDD806905 inhibits Leishmania in vitro translation. (A) In vitro translation in a Leishmania tarentolae extract was monitored over time by tracking expression of an eGFP construct (closed circles), with a “minus construct” negative control included (open circles). (B) The ability of DDD806905 to inhibit expression of eGFP in the L. tarentolae extract was investigated with this LdMetRS inhibitor inhibiting protein synthesis with an EC₅₀ of 2.2 μM (closed circles). In the presence of an additional 1.5 mM methionine, the EC₅₀ was shifted to 12 μM (open circles), indicative of on-target activity, as DDD806905 is a known methionine competitive inhibitor of LdMetRS. (C) In vitro translation in a HeLa cell extract was also monitored by tracking expression of a GFP construct (closed circles) over time, with “minus construct” (closed triangles) and cycloheximide (protein synthesis inhibitor) controls (open circles) included. When DDD806905 was included at a concentration of 100 μM (open triangles), no inhibition of in vitro translation was observed in this human cell extract. Data are shown as mean ± SD (n = 3 technical replicates (cycloheximide data, n = 2 technical replicates)).