The objective of our research is to understand the reaction mechanisms involved in charge transfers within redox proteins that contain flavin and/or heme. NADPH oxidase is part of this family of proteins, as its function requires redox intermediates such as FAD and hemes, which facilitate transmembrane electron transfers to produce the superoxide anion. In collaboration with theoretical teams from ICP and LBT (Paris), we conducted the first atomic simulations of NADPH oxidase embedded in a lipid membrane, along with initial estimates of the thermodynamic parameters and inter-heme electron transfer pathways [Wu 2021]. This approach was previously validated for identifying intramolecular electron transfer pathways in another flavohemoprotein [Ezzine2014)] namely soluble flavohemoglobin, which is involved in the defense mechanisms of microorganisms [ElHammi2012] , and confirmed kinetically through pulsed radiolysis coupled with time-resolved absorption spectroscopy. These studies provide insights for the development of inhibitors [Butcher2020], proposing a novel therapeutic concept for redox-active antimicrobial and antifungal agents [Moussaoui2018], for which we have clearly established the reaction mechanism [Pasquier2023].