Histone H4 is one of four core histone proteins, the others being H3, H2B, and H2A, that are involved in the organization of DNA into chromatin. Histones are subject to a variety of posttranslational modifications, such as methylation, acetylation, and citrullination, that can influence chromatin structure and regulate gene transcription. Histone H4 can be citrullinated at the arginine residue at position 3 (H4R3) by protein arginine deiminase 4. Citrullination of H4R3 increases in U2OS cells following induction of DNA damage by adriamycin and is localized near fragmented nuclei. H4R3 citrullination is associated with smaller tumor size and inversely associated with p53 levels in tumor tissue samples derived from patients with non-small cell lung cancer (NSCLC). Citrullinated histone H4 is present in neutrophil extracellular traps (NETs) generated by stimulation of granulocytes with phorbol 12-myristate 13-acetate (PMA) and can be recognized by autoantibodies present in the serum of patients with rheumatoid arthritis. 052588 is derived from purified recombinant human Histone H4, that has been modified with PAD4 enzyme, which is subsequently depleted by affinity chromatography. Full length recombinant protein corresponding to aa1-103 from human Histone H4, citrullinated with human recombinant PAD4, expressed in E. coli. Swiss/Uniprot Accession: P62805 Molecular Weight: ~11.5kD Storage and Stability: Aliquot to avoid repeated freezing and thawing and store at -70C. Aliquots are stable for 6 months after receipt. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
