ASS1 Human

Argininosuccinate Synthase 1 (ASS1) is a crucial enzyme in the urea cycle, responsible for catalyzing the formation of argininosuccinate from citrulline and aspartate. This reaction is a key step in the biosynthesis of arginine, a semi-essential amino acid. The enzyme is encoded by the ASS1 gene in humans .

ASS1 plays a pivotal role in the urea cycle, which is essential for detoxifying ammonia in the liver. The enzyme’s activity ensures the conversion of toxic ammonia into urea, which is then excreted from the body. Additionally, ASS1 is involved in the production of nitric oxide, a critical signaling molecule, and in the synthesis of polyamines, which are important for cell growth and differentiation .

Mutations in the ASS1 gene can lead to citrullinemia type I, a rare genetic disorder characterized by the accumulation of citrulline and ammonia in the blood. This condition can cause severe neurological symptoms and, if untreated, can be fatal. Recombinant human ASS1 is used in research and therapeutic applications to study and potentially treat this disorder .

Recent studies have highlighted the role of ASS1 in cancer metabolism. Tumor cells often exhibit altered metabolic pathways to support rapid growth and survival. ASS1 expression is frequently downregulated in various cancers, making these cells auxotrophic for arginine. This dependency on external arginine can be exploited for therapeutic purposes. Arginine deprivation therapy, which targets ASS1-deficient tumors, has shown promise in preclinical and clinical studies .

Recombinant human ASS1 is used in various therapeutic applications, including enzyme replacement therapy for citrullinemia and as a potential treatment for ASS1-deficient cancers. By restoring ASS1 activity, these therapies aim to correct metabolic imbalances and inhibit tumor growth .