Bacterial arginine deiminase system enzymes (ADS)

The Bacterial Arginine Deiminase System (ADS) is a crucial metabolic pathway found in various bacteria, consisting primarily of three enzymes: arginine deiminase (ADI), ornithine carbamoyltransferase (OTC), and carbamate kinase (CK). This system facilitates the catabolism of L-arginine into citrulline, ammonia, and carbon dioxide, while simultaneously generating ATP for the cell [PMID: 26055536]. Biologically, the ADS serves as a vital defense mechanism against acid stress, as the production of ammonia helps maintain an intracellular pH compatible with survival, which is particularly important for dental health and the persistence of pathogens in host environments [Source: NIH/NCBI]. In oncology, the ADI enzyme itself has been developed into a therapeutic agent known as pegargiminase (ADI-PEG 20), which exploits the arginine auxotrophy of certain cancers by depleting systemic arginine [Source: ClinicalTrials.gov]. Conversely, inhibiting this system in pathogenic bacteria is being explored as a strategy to reduce virulence and increase sensitivity to host immune responses [PMID: 29437116]. Therapeutic challenges include the potential for immunogenic reactions to the bacterial-derived enzymes and the metabolic impact on host nitric oxide synthesis [Source: PubChem].

Other names

Arginine deiminase pathwayADI pathwayArc systemBacterial arginine metabolism enzymes

The system catalyzes the conversion of L-arginine into ammonia and citrulline, providing ATP and neutralizing acidic environments via ammonia production; therapeutically, exogenous bacterial ADI depletes systemic arginine to starve auxotrophic tumor cells.