Anti-Citrullinated Fibrinogen Immunoglobulin, clone 20B2 (Monoclonal) [Mouse]

Fibrinogen is a protein produced by the liver which helps stop bleeding by helping blood clots to form. Fibrinogen gets deiminated (conversion from arginin to citrullin) by Peptidyl Arginine Deïminase (PAD) in inflamed joints in patients that develop rheumatoid arthritis. Citrulline, while being an amino acid, is not built into proteins during protein synthesis, as it is not coded for by DNA, yet several proteins are known to contain citrulline. Proteins that normally contain citrulline residues include myelin basic protein (MBP), filaggrin, and several histone proteins, while other proteins, like fibrin and vimentin can get deiminated during cell death and tissue inflammation. Patients with rheumatoid arthritis often (at least 80% of them) develop an immune response against proteins containing citrulline. Although the origin of this immune response is not known, detection of antibodies reactive with citrullinecontaining proteins or peptides is now becoming an important help in the diagnosis of rheumatoid arthritis. Protein function: Cleaved by the protease thrombin to yield monomers which, together with fibrinogen beta (FGB) and fibrinogen gamma (FGG), polymerize to form an insoluble fibrin matrix. Fibrin has a major function in hemostasis as one of the primary components of blood clots (PubMed:7649481). In addition, functions during the early stages of wound repair to stabilize the lesion and guide cell migration during re-epithelialization (PubMed:11389004). Was originally thought to be essential for platelet aggregation, based on in vitro studies using anticoagulated blood (PubMed:7649481). However, subsequent studies have shown that it is not absolutely required for thrombus formation in vivo (PubMed:10930441). Enhances expression of SELP in activated platelets via an ITGB3-dependent pathway (PubMed:19332769). Maternal fibrinogen is essential for successful pregnancy (PubMed:7649481). Fibrin deposition is also associated with infection, where it protects against IFNG-mediated hemorrhage (PubMed:12629066). May also facilitate the immune response via both innate and T-cell mediated pathways (PubMed:23487423). [The UniProt Consortium]