Nitrogen metabolism (reduction and fixation) (map00910)

Nitrogen metabolism (reduction and fixation) is a comprehensive biological pathway rather than a single molecule or receptor. It encompasses the biochemical processes by which organisms convert inorganic nitrogen compounds, such as nitrate and nitrite, into organic forms like ammonia and amino acids. In human medicine, the modulation of this pathway is critical for treating hyperammonemia and hepatic encephalopathy, typically through nitrogen-scavenging agents like glycerol phenylbutyrate that provide alternative pathways for nitrogen excretion. In oncology, nitrogen metabolism is frequently 'rewired,' with many tumors exhibiting a high dependency on glutamine-derived nitrogen for biosynthetic processes, making specific enzymes like glutaminase attractive targets for therapeutic inhibition. Additionally, the unique nitrogen reduction pathways used by pathogens such as Mycobacterium tuberculosis for survival in anaerobic host environments are being investigated as novel antimicrobial targets. Therefore, while not a single target entity, 'Nitrogen metabolism reduction' represents a major therapeutic goal across metabolic, infectious, and neoplastic diseases.

Other names

Nitrogen metabolism (reduction and fixation) pathwayNitrate reduction pathwayNitrogen assimilationAmmonia metabolismKEGG map00910

Modulation of nitrogen flux through this pathway is achieved by nitrogen scavenging (conjugating with glutamine or glycine for excretion), enzymatic inhibition of key steps like glutaminolysis, or enhancement of the urea cycle to reduce systemic ammonia levels.