This peptide is histone H4 (1-23) with deimination at Arg3. It contains a C-terminal GGK linker with biotinylation on the side chain of this Lys. Deimination of Arg3 to Cit is carried out by peptidylarginine deiminase (PADI)-4. Although the function of deimination is not clearly known, it has been shown to inhibit Arg methylation and repress nuclear hormone receptor-dependent gene activation. Provided at >95% peptide purity, this peptide was dissolved in distilled water at 1 mg/ml and re-lyophilized to powder form.