Citrullination – small change with a great consequence

Abstract

<jats:p>Citrullination is one of the possible post-translational modifications of proteins. It is based on a conversion of L-arginine residue (L-Arg) to L-citrulline residue (L-Cit). The reaction is catalyzed by peptidylarginine deiminases (PAD). The change of L-Arg imino moiety results in a loss of a positive charge. This slight modification can contribute to significant changes in physicochemical properties of proteins, which may also cause a change of their functions. Citrullination is the modification observed in physiological processes such as epidermal keratinization, regulation of gene expression and the reorganization of myelin sheaths. The changes in the efficacy of citrullination may contribute to the pathogenesis of many different diseases including: psoriasis, multiple sclerosis, rheumatoid arthritis and cancer.</jats:p>

Autoantibodies as Diagnostic Markers and Mediator of Joint Inflammation in Arthritis

“…The citrullinated proteins are often found in the joints of RA patients but are not specific for the disease. In general, the citrullination of the protein may alter its tertiary structure, interaction with other molecules, cleavage regions, and its solubility to enhance its immunogenicity, which could stimulate the immune response to produce corresponding antibodies [21, 22]. It has been found that a large number of abnormally proliferating macrophages and lymphocytes infiltrate into the synovial tissue of RA patients.…”