Cl-Amidine (hydrochloride) is an irreversible pan-peptidylarginine deiminase (PAD) inhibitor. It catalyzes the post-translational modification of arginine residues on histones to form citrulline. The in vitro IC₅₀ values are 5.9 ± 0.3 μM, 0.8 ± 0.3 μM, 6.2 ± 1.0 μM for PAD4, PAD1 and PAD3, respectively. It causes apoptosis in multiple cancer cell lines such as HL60, HT29, TK6, and U2-OS cells. It improves disease phenotypes in animal models of inflammatory arthritis and inflammatory bowel disease. It reduces the development of IgG autoantibodies in a collagen-induced mouse model of inflammatory arthritis.
