Bacterial nitric oxide synthase oxygenase (bNOS)

Bacterial nitric oxide synthase oxygenase (bNOS) is a key enzyme found in several Gram-positive pathogens, including Staphylococcus aureus and Bacillus anthracis, where it facilitates the production of nitric oxide (NO) from L-arginine (Gusarov et al., 2009, Science). Unlike mammalian nitric oxide synthases, which are large multidomain proteins, bNOS typically consists only of the oxygenase domain and relies on available cellular reductases to complete its catalytic cycle (Holden et al., 2013, Nature). The NO produced by bNOS serves as a critical defense mechanism, protecting the bacteria from oxidative stress induced by host immune cells and increasing resistance to various antibiotics like vancomycin (Shatalin et al., 2008, Nature). By modulating bacterial physiology and virulence, bNOS has become a significant target for the development of antivirulence drugs that can potentiate existing antimicrobial therapies (He et al., 2020, J. Med. Chem.). Current drug discovery efforts focus on small-molecule inhibitors that can selectively bind the bNOS active site while avoiding the highly similar human NOS isoforms (eNOS, nNOS, and iNOS) to prevent systemic side effects (Cinelli et al., 2014, J. Med. Chem.).

Other names

bNOSbNOSoxyBacterial nitric oxide synthaseNitric oxide synthase (bacterial)

Competitive inhibition of the bNOS oxygenase domain prevents the conversion of L-arginine to nitric oxide, thereby increasing bacterial susceptibility to oxidative stress and potentiating the efficacy of conventional antibiotics.