CPS1 (N-Term) Rabbit Monoclonal Antibody (RM395)

Carbamoyl phosphate synthetase I (CPS1) is a ligase involved in the urea cycle.¹ It is composed of an N-terminal domain containing an ancestral inactive glutaminase, a bicarbonate phosphorylation site, and a C-terminal domain containing a carbamate phosphorylation site and the binding site for the CPS1 allosteric activator N-acetyl-L-glutamate (NAG). It is primarily expressed in the liver and intestinal epithelial cells and is localized to the mitochondrial matrix.^2,1 CPS1, with NAG as a cofactor, catalyzes the formation of carbamoyl phosphate from ammonia, bicarbonate, and ATP as the first, rate-limiting step in the urea cycle. Mutations in CPS1 result in CPS1 deficiency, a disorder characterized by low levels of active CPS1, arginine, and citrulline and high levels of ammonia and glutamine, leading to neurological deficits and, potentially, death.^3,4 Protein levels of CPS1 are increased in patient-derived rectal cancer tumors and associated with shorter disease-specific survival and metastasis-free survival.⁵ Cayman’s CPS1 (N-Term) Rabbit Monoclonal Antibody (RM395) can be used for immunohistochemistry (IHC) and Western blot (WB) applications.

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1. Martínez, A.I., Pérez-Arellano, I., Pekkala, S., et al. Genetic, structural and biochemical basis of carbamoyl phosphate synthetase 1 deficiency. Mol. Genet. Metab. 101(4), 311-323 (2010).

2. Ryall, J.G., Nguyen, M., Bendayan, M., et al. Expression of nuclear genes encoding the urea cycle enzymes, carbamoyl-phosphate synthetase I and ornithine carbamoyl transferase, in rat liver and intestinal mucosa. Eur. J. Biochem. 152(2), 287-292 (1985).

3. Nitzahn, M., and Lipshutz, G.S. CPS1: Looking at an ancient enzyme in a modern light. Mol. Genet. Metab. 131(3), 289-298 (2020).

4. Pekkala, S., Martínez, A.I., Barcelona, B., et al. Understanding carbamoyl-phosphate synthetase I (CPS1) deficiency by using expression studies and structure-based analysis. Hum. Mutat. 31(7), 801-808 (2010).

5. Lee, Y.-Y., Li, C.-F., Lin, C.-Y., et al. Overexpression of CPS1 is an independent negative prognosticator in rectal cancers receiving concurrent chemoradiotherapy. Tumour Biol. 35(11), 11097-11105 (2014).