Nitrosative stress and NO detoxifying reaction mechanisms in microbial nonheme diiron proteins

PROJECT SUMMARY Metalloenzymes play crucial roles throughout human health and govern the biochemistry of dioxygen (O2) and nitric oxide (NO). Pathogenic organisms depend on heme and nonheme iron-containing proteins to counter the human immune response and to survive exposure to high concentrations of reactive oxygen and nitrogen species (ROS/RNS). The Moënne-Loccoz Lab combines classic biochemical techniques, resonance Raman (RR), FTIR, and EPR spectroscopies with time-resolved techniques to probe microbial enzymatic systems characterized by X-ray crystallography, but with catalytic strategies that remain poorly understood or totally unknown. In this project, a recent crystal structure of a novel mycobacterial diiron protein upregulated upon macrophage infection is targeted for investigation after showing unique structural features and reactivity toward RNS never seen before in biology or inorganic chemistry.