Michel Simon

Peptidylarginine Deiminases and Protein Deimination in Skin Physiopathology

Post-translational modifications of proteins are crucial because they may alter the physical and chemical properties, folding, distribution, stability, activity, and consequently the functions of the targets, some of which being involved into diseases. Recently, one of these post-translational modifications, deimination (also called citrullination), became of an increasing concern. It corresponds to the conversion of protein-bound arginine residues to citrulline residues in the presence of calcium ions (Figure 1). This modification dramatically alters the charge of residues from positive to neutral, probably resulting for the targets in loss of conformation, in aggregation ability, or in depolymerization tendency. Peptidylarginine deiminases (PADs, EC 3.5.3.15) have been found as the enzymes that catalyze deimination (Rogers and Taylor, 1977; Sugawara et al., 1982; Takahara et al., 1983). These enzymes belong to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in linear amidines.