PF-3166

PF-3166 (concentration series; 30-minute preincubation) inhibits total citrullination in Ionomycin (HY-13434)-stimulated human neutrophils with an IC₅₀ of 3 μM and an I_max of ~70%, supporting cellular-level PAD2 inhibition^[1].

PF-3166 (10-minute preincubation) inhibits recombinant human PAD2 with an IC₅₀ of 150 nM in the FQ assay and shows no inhibition of PAD3 or PAD4 at concentrations up to 80 μM^[1].
PF-3166 (10-minute preincubation) inhibits recombinant human PAD2 with an IC₅₀ of 580 nM in the ammonia release assay^[1].
PF-3166 (serial dilution) inhibits recombinant human PAD2 in the GDH-coupled assay with an IC₅₀ of 610 nM under 0.25 mM Ca²⁺ conditions and 5.47 μM under 1.5 mM Ca²⁺ conditions, consistent with competitive inhibition with respect to Ca²⁺ , and does not inhibit PAD4^[1].
PF-3166 (10 μM) binds recombinant human PAD2 in ASMS with K_D = 221 nM, and no PAD4 binding is detected^[1].
PF-3166 (10-20 μM; 25-99°C, 0.06°C/s) stabilizes PAD2 by 9-12°C in thermal shift assays without destabilizing PAD4, and its binding is Ca²⁺ -competitive, with no increase in ΔT_m under 400 μM Ca²⁺ conditions and a decrease in ΔT_m under 10 mM Ca²⁺ conditions^[1].
PF-3166 (1-30 mM; 1-2 h) binds the PAD2 dimer interface at 1.64 Å resolution with a 2:1 stoichiometry and allosterically inhibits PAD2 by displacing Ca²⁺ from CA1 and blocking CA2^[1].