Arginase-1 (ARG1) Monoclonal Antibody (UMAB288), UltraMAB™

Target Information

Arginase-1 (Arg1) is a 35 kDa enzyme converting L-arginine to urea and L-ornithine, which is the final step in the urea cycle. The resulting polyamines are important for cell proliferation and removal of toxins that arise from protein degradation. By degrading arginine, Arginase 1 deprives NO synthase of its substrate and down-regulates nitric oxide production. In both human and mouse, Arginase 1 is expressed in the liver, neutrophils, myeloid derived suppressor cells (MDSC) and neural stem cells. In human, expression in blood neutrophils but not in CCR3+ granulocytes has been reported. In mice, expression of Arginase 1 is one of the hallmarks of alternatively activated macrophages (M2a). Arginase-1 may be expressed in the myeloid cells infiltrating tumors, and is typically found in the majority of hepatocellular carcinomas. Defects in Arginase 1 are the cause of argininemia, an autosomal recessive disorder characterized by hyperammonemia.