A reactive intermediate capable of transferring its carbamoyl group to an acceptor molecule, forming citrulline from ornithine in the urea cycle, and ureidosuccinic acid from aspartic acid in pyrimidine ring formation.
- c. synthetase a phosphotransferase catalyzing the formation of c.. There are two significant isozymes. Carbomoyl phosphate synthetase I is a mitochondrial enzyme that catalyzes the reaction of 2ATP, NH3, CO2, and H2O to c., 2ADP, and orthophosphate. It is activated by N-acetylglutamate and participates in urea biosynthesis. A deficiency of c. synthetase I can result in hyperammonemia. C. synthetase II is a cytosolic enzyme that, under physiological conditions, uses l-glutamine as the nitrogen source (producing l-glutamate) instead of NH3, is not activated by N-acetylglutamate, and participates in pyrimidine biosynthesis.
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an important intermediate compound in the formation of pyrimidine and citrulline, the latter being an intermediate in urea formation.Medical dictionary. 2011.