- 2011 ). On the other side, plants have developed some enzymatic systems including superoxide dismutases (SOD), catalases (CAT), ascorbate peroxidases (APX), peroxiredoxins and non-enzymatic mechanisms to protect against oxidative damage caused by these ROS (Agrawal et al. (springeropen.com)
- Based on this mechanism, both activities should be mutually antagonistic and peroxidatic electron donors should inhibit the catalase activity. (auburn.edu)
- In fact, it has been established that the common peroxidatic electron donor o-dianisidine does inhibit the catalase activity of KatG from Escherichia coli at pH 7.5. (auburn.edu)
- The role of GSH and catalase were also investigated by treating the Malignant Pleural Mesothelioma cells and A549 adenocarcinoma cells with buthionine sulfoximine (BSO), to block glutathione synthesis, and aminotriazole (ATZ) to inhibit catalase. (charismaticplanet.com)
- As the name suggests, they catalyze the decomposition of H2O2 by catalatic and peroxidatic mechanisms using a single active site. (auburn.edu)
- KatGs are heme-dependent enzymes and are primarily known as H2O2 scavengers. (auburn.edu)
- Conversely, catalase activity can sustain high concentrations of H2O2 without the enzyme inactivation. (auburn.edu)
- In the absence of a peroxidatic electron donor, we observed a "low-KM" and "high-KM" component for catalase activity at pH 5.0. (auburn.edu)
- The ability of one activity to dominate over the other depends on several factors including: pH, the concentration of H2O2, and the availability of an appropriate exogenous electron donor. (auburn.edu)
- Catalase activity is optimal near neutral pH (i.e., pH ~ 7.5), whereas peroxidase activity is optimal under acidic conditions (i.e., pH ~ 4.5) and requires an exogenous electron donor. (auburn.edu)
- More so, peroxidase activity is favorable at low H2O2 concentrations. (auburn.edu)
- Clearly, conditions which favor the peroxidase activity do not coincide with those that favor the catalase activity. (auburn.edu)
- Strikingly, in this dissertation, we report the dramatic stimulation of the catalase activity of KatG from Mycobacterium tuberculosis (MtKatG) by up to 14-fold, in the presence of several common peroxidatic electron donors. (auburn.edu)
- The stimulatory effect was most prominent under conditions favorable to peroxidase activity (i.e., acidic pH and low H2O2 concentrations). (auburn.edu)
- During stimulated catalase activity, very little of the donor (0.008 eq. (auburn.edu)
- intermediate dominated during electron donor-stimulated catalase activity of MtKatG, and this intermediate converted directly to the ferric state upon depletion of H2O2. (auburn.edu)
- Moreover, this study has elucidated that SA‐induced stomatal closure involves extracellular oxidative burst (Figs 2 & 3) and that the extracellular oxidative burst is mediated with SHAM‐sensitive peroxidases but not NAD(P)H oxidases (Figs 1d & 2). (rehabsociety.org.hk)