Carbamoyl phosphate

Carbamoyl phosphate is an anion of biochemical significance. In land-dwelling animals, it is an intermediary metabolite in nitrogen disposal through the urea cycle and the synthesis of pyrimidines. Its enzymatic counterpart, carbamoyl phosphate synthetase I, interacts with a class of molecules called sirtuins, NAD dependent protein deacetylases, and ATP to form carbamoyl phosphate. CP then enters the urea cycle in which it reacts with ornithine to form citrulline.

Classification

Carbamoyl phosphate is a metabolic intermediate in a pathway that involves nitrogen disposal through the urea cycle and the biosynthesis of pyrimidines.

Production

It is produced from bicarbonate, ammonia, and phosphate. The synthesis is catalyzed by the enzyme carbamoyl phosphate synthetase. This uses three reactions as follows:

+ ATP → ADP +
+ NH₃ + OH⁻ → + ⁻O–C(O)NH₂ + H₂O
⁻O–CNH₂ + ATP → ADP +

Clinical significance

A defect in the CPS I enzyme, and a subsequent deficiency in the production of carbamoyl phosphate has been linked to hyperammonemia in humans.