Back to article: Direct detection of stringent alarmones (pp)pGpp using malachite green
FIGURE 3: Identification of novel chemical inhibitors of SpoT HYD activity. (A) Hydrolysis of ppGpp (in µM) by SpoT SYNoff in the absence (PC) or presence of two ppGpp chemical analogues (DR-5839A, DR-6459). Unpaired t-test significance was displayed (** p-value < 0.005). (B, C) Chemical structures of (B) DR-5839A and (C) DR-6459. (D, E) Test if DR-5839A and DR-6459 can be a substrate of SpoT HYD activity using MG. NC, the SpoT HYD reactions were similarly set up, but MG working reagent was added immediately to stop the HYD reaction. (F) Chemical structure of thermorubin. (G, H) IC50 measurement of both thermorubin (G) and DR-5839A (H). The activities shown in percentage were normalised to the sample without the respective chemical. The mean ± SD of three technical replicates were plotted.