Polypeptide combined with immune antibody and application thereof

Abstract

The invention relates to a polypeptide combined with an immune antibody. Three arginine side chains in sequences of the polypeptide are modified to be electrically neutral or electronegative amino acid; and two non-adjacent cysteine side chain mercapto groups on the polypeptide sequences forms annular disulfide bonds. The polypeptide can be combined with the autoimmune antibody of rheumatoid arthritis and can have high affinity to HLA-DR. The experimental result shows that the specificity of the polypeptide combined with the autoimmune antibody of the rheumatoid arthritis is over 75 percent. Compared with the like products sold in the market, the polypeptide has the advantage that: the sensitivity of the polypeptide is obviously improved so as to more contribute to the detection in vitro for the autoimmune antibody of the rheumatoid arthritis.

Description

technical field The present invention relates to a polypeptide that binds to immune antibodies, in particular to a polypeptide that binds to rheumatoid arthritis immune antibodies, and more specifically relates to a polypeptide that has three arginines modified and binds to rheumatoid arthritis autoimmune antibodies peptide. Background technique Clinically, autoimmune diseases mainly include systemic lupus erythematosus, rheumatoid arthritis, Sjogren's syndrome, dermatomyositis, polymyositis, systemic (multiple) sclerosis, scleroderma, etc. These diseases were once named " Connective tissue disease", later both abroad and domestically classified them as rheumatic diseases. Rheumatoid arthritis (RA) is a relatively common systemic autoimmune disease mainly manifested by chronic polyarticular inflammation. Very painful. The incidence of the disease is 0.5-1% worldwide, and the incidence in China is about 0.36%. The age of onset of patients is mostly between 20 and 50 year...

AI Technical Summary

Problems solved by technology

64% of patients with rheumatoid arthritis can produce antibodies directly against BiP, and there are reports that it is highly specific to the disease, but there is no data to support the role of BiP in predicting rheumatoid arthritis, and these reports The BiP antibody still needs to be confirmed by independent clinical research (Clinica Chimica Acta 2004, 350, 17-34)

It must be noted that, as RF is included in the ACR criteria, its sensitivity in the diagnosis of rheumatoid arthritis cannot be directly compared with those of other methods not included in the diagnostic criteria

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