Carbamoyl Phosphate Synthetase (CPS)

Carbamoyl Phosphate Synthetase (CPS) is an enzyme involved in nitrogen metabolism and pyrimidine synthesis. It exists in two isoforms, CPS I and CPS II, based on their location and function. CPS I primarily operates in the mitochondria of the liver, participating in the first step of the urea cycle. It catalyzes the synthesis of carbamoyl phosphate from ammonia (NH₃) and carbon dioxide (CO₂) in the presence of ATP, helping to convert excess ammonia in the body into non-toxic urea for excretion. CPS II, on the other hand, is mainly found in the cytoplasm and is involved in the biosynthesis of pyrimidine nucleotides. The carbamoyl phosphate it catalyzes is used to synthesize pyrimidine precursors, thereby supporting DNA and RNA synthesis.
Carbamoyl Phosphate Synthetase plays a crucial role in metabolism and physiological processes. CPS I deficiency is a hereditary metabolic disorder that leads to impaired urea cycle function, causing the accumulation of ammonia in the body, resulting in hyperammonemia, which can trigger coma, seizures, and other neurological symptoms. CPS II deficiency may lead to abnormal pyrimidine synthesis, affecting cell proliferation and immune function, and is associated with the occurrence and progression of certain cancers^[1].