Enzyme that citrullinates arginine residues on histones, regulating gene expression and implicated in rheumatoid arthritis and cancer. Recombinant full length human PAD4 was expressed by baculovirus in Sf9 insect cells using an N-terminal GST tag. Molecular weight 96 kDa. Supplied as sterile 50 mM Tris-HCl pH 7.5, 50-300 mM NaCl, 1 mM DTT, 10-25% glycerol. Store product at –70°C. For optimal storage, aliquot target into smaller quantities. Avoid repeated handling and multiple freeze/thaw cycles.