Recombinant E. coli ASS1 protein (Active)

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

ASS1 or argininosuccinate synthase 1 is an enzyme that plays an important role in the urea cycle. It catalyzes the conversion of citrulline and aspartate into argininosuccinate using ATP in the process. The ASS1 protein is commonly expressed in the liver where it actively participates in the detoxification of ammonia. It has a molecular mass of approximately 46 kDa. Some alternate names for this protein include ASS and ASS-1.

Biological function summary

Argininosuccinate synthase 1 contributes significantly to the synthesis of arginine an essential amino acid through its conversion activities. The enzyme operates as a homotrimer a complex consisting of three identical subunits. This enzymatic activity is indispensable in maintaining the balance of nitrogen and ammonia within the body particularly important for liver and kidney functions.

Pathways

ASS1 is a critical component of both the urea cycle and the nitric oxide metabolism pathway. The urea cycle helps in detoxifying ammonia by converting it into urea which is excreted in urine. In nitric oxide metabolism ASS1 links with nitric oxide synthase to facilitate the use of arginine in producing nitric oxide a vital signaling molecule. The pathway engagement partners include proteins like citrin which supplies aspartate for the reaction.

ASS1 has implications in citrullinemia and hepatocellular carcinoma. Citrullinemia results from mutations in the ASS1 gene leading to defective urea cycle function and ammonia accumulation. In cancer particularly hepatocellular carcinoma low expression of ASS1 correlates with poor prognosis as cancer cells often exhibit arginine auxotrophy. Connections through these conditions involve interactions with enzymes such as arginase which also influences arginine availability.