Arginine Deiminase (ADI) is a microbial enzyme from Mycoplasma produced in E.coli. It has high affinity to L-arginine and hydrolyzes L-arginine to citrulline and ammonia. Low concentrations of ADI have been shown to inhibit proliferation in certain cultured cells by arresting the cell cycle in G (1) and/or S phase. Higher concentrations of ADI lead to subsequent apoptosis. Recombinant Mycoplasma Arginine Deiminase is a 46.4 kDa protein consisting of 409 amino acids.