Comparación Estructural entre los Péptidos Usados en la Detección Inmunoenzimática de la Artritis Reumatoide y sus Correspondientes Secuencias en las Proteínas Nativas.

Abstract

Rheumatoid Arthritis is an autoimmune disease characterized by inflammation and joint destruction. Although its cause is unknown, environmental, endocrine and genetic factors have been identified, which are related with the development of the disease. Until recently, the determination of rheumatoid factors, was the only test used for the study of this disease. This technique is not very sensitive or specific, and it is positive for other diseases. Recent studies have shown that sera from patients with arthritis, recognized synthetic cyclic peptides containing the amino acid citrulline (X) by ELISA assays. Antibodies against cyclic citrullinated peptides are highly specific for rheumatoid arthritis and are present in at least 60-75 % of the patients studied, with a specificity of 95-100 %. This high specificity combined with its presence in the early disease, even before the disease is manifested, suggest an important role of these antibodies in the pathogenesis of the disease. In this work we analyzed the sequence of those peptides, ARGHXPLDKKREEAPSLXPA and HSTKRGHAKSRPVXG with DELTA-BLAST program. Then, the three-dimensional structure of proteins was calculated. The structural analysis of peptide sequences showed that these peptides can be redesigned to obtain better structural mimics. These redesigned peptides are expected to improve affinity and specificity in ELISA assays and may contribute to the early diagnosis of Rheumatoid Arthritis.