A Study On A Study On The Interaction Between PTPN22 And PADI4

Rheumatoid arthritis is a common, chronic, autoimmune disorders of autoimmunity disease, it is found clinically that the main characteristic of RA is inflammation in areas such as the joints, bones, necrosis of joint and bone erosion would be caused in the disease process,that will eventual ly lead to joint deformity and afunction. The cause of RA is unclear. PTPN22,protein tyrosine phosphatase nonreceptor 22,now think of the gene encoding the lymphatic tyrosine phosphatase can influence T cell activation, thus affect the immune steady and lead to autoimmune diseases. PADI4, namely the peptidyl arginine deiminase typ e IV, arginine conversion to citrulline residues for coding the members of the family of enzymes, which in available in granulocyte and macrophage mediated play a role in inflammation and immune response, so it can be associated with the on set of rheumatoid arthritis. PADI4 is a posttranslational modification enzyme, can be in the presence of calcium ions to arginine residues into citrulline residues, this process is called citrulline. Alterations in protein citrullination may also explain some of the risk factors for RA. Studies have shown that PTPN22 interacts with PAD4 to limit citrullination and the formation of neutrophil extracellular traps. PTPN22 is a natural inhibitor of PAD4. The R620-to-W620 conversion completely deprives PTPN22 of this inhibitory ability and results in hypercitrullination. And at present for PTPN22 and PADI4 structure, the mechanism still is not very clear, is the main limiting factors and PTPN22 PADI4 protein purification which may lead to a difficult protein crystallization, causing the lack of data.In order to solve this problem, this paper explores the PTPN22 and PADI4 protein in the prokaryotic expression system can be high level expression, through optimizing the cultivation of the e. coli, temperature, cultivation time and concentration can improve the expression of protein content, activity and purity. By means of affinity purification, ion exchange, gel fitration, the protein will be of higher purity and concentration.PTPN22 and PADI4 protein. The purified PTPN22 and PADI4 protein, there is no interaction between them. Some of PTPN22 recombinant proteins and PADI4 protein can be co-expression. This research deepened our overall understanding of PTPN22 and PADI4 protein, structure analysis and clinical application of diagnosis for the future lay a good foundation.