PAD2-IN-1, a benzimidazole-based derivative, is an efficacious and specific inhibitor of protein arginine deiminase 2 (PAD2). Demonstrating remarkable selectivity, PAD2-IN-1 exhibits a 95-fold higher affinity for PAD2 in comparison to PAD4 and a 79-fold higher affinity than PAD3.
Cl-amidine is an orally active inhibitor of peptidyl arginine deminase (PAD) (IC50s: 0.8 μM, 6.2 μM, and 5.9 μM for PAD1, PAD3, and PAD4). Cl-amidine induces apoptosis in cancer cells.
Streptonigrin is a natural product produced by Streptomyces flocculus, has both anti-tumor and anti-bacterial activity. Streptonigrin acts as a pan-PAD inhibitor (IC50s: 48.3±34.2 µM, 26.1±0.3 µM, 0.43±0.03 µM, and 2.5±0.4 µM for PAD1, PAD2, PAD3, and PAD
BB-Cl-Yne is a cell-permeable derivative of the protein arginine deiminase (PAD) inhibitor BB-Cl-amidine that contains an alkyne moiety for use in click chemistry reactions. BB-CL-Yne inhibits PAD1-4 with Kinact/KI values of 6,400, 3,600, 10,800, and 4,900 M-1min-1, respectively. It has been used for labeling PADs in cell-free and cell-based assays, followed by click reactions with azide-modified TAMRA or biotin reporters.
F-amidine is a selective inhibitor of protein arginine deiminases (PADs), specifically targeting PAD1 and PAD4 with in vitro IC50 values of 29.5, 350, and 21.6 µM for PAD1, PAD3, and PAD4, respectively. It irreversibly inactivates all four PAD subtypes by covalently modifying an active site cysteine crucial for enzymatic activity, with kinact/KI values of 2,800, 380, 170, and 3,000 M^-1min^-1. Additionally, F-amidine demonstrates cytotoxicity against HL-60, MCF-7, and HT-29 cancer cell lines, with IC50s of 0.5, 0.5, and 1 μM, respectively.