
<ArticleTitle>Immunocytochemical localization of <prot>peptidylarginine deiminase</prot> in human eosinophils and neutrophils.</ArticleTitle>
<AbstractText><prot>Peptidylarginine deiminase</prot>, registered as <prot>PAD V</prot> in the DDBJ/GenBank/EMBL data banks, is expressed in HL-60 cells differentiated into granulocytes or monocytes. We analyzed PAD activities in density-fractionated human peripheral blood cell fractions. PAD activity with similar substrate specificity to that of <prot>PAD V</prot> was found in the eosinophil and neutrophil fractions, which showed single bands comigrating with authentic <prot>PAD V</prot> on immunoblotting with an anti-<prot>PAD V</prot> antibody. Both the biochemical and immunoblotting analyses showed marked enrichment of <prot>PAD V</prot> in the eosinophil fraction. Its immunoreactivity appeared to localize in eosinophilic granules at high density and in myeloperoxidase-negative cytoplasmic granules of neutrophils at low density, as determined by confocal laser-scanning microscopy. Possible roles of <prot>PAD V</prot> in myeloid differentiation and granulocyte function are discussed. In addition, we present evidence for the presence of PAD(s) that are antigenically different from <prot>PAD V</prot> in monocytes and lymphocytes.</AbstractText>
