PTPN22與PADI4相互作用的研究
發(fā)布時間:2018-04-16 02:19
本文選題:類風濕關節(jié)炎 + PTPN22; 參考:《哈爾濱工業(yè)大學》2015年碩士論文
【摘要】:類風濕關節(jié)炎是一種常見的、慢性的、自身免疫系統(tǒng)失調的自身性免疫疾病。臨床發(fā)現(xiàn)該病的主要特征是關節(jié)、骨骼等部位發(fā)生炎癥,發(fā)病過程中引發(fā)關節(jié)的壞死以及骨骼的侵蝕,最終將導致患者關節(jié)的畸形及其功能的喪失。類風濕關節(jié)炎的病因尚不明確。PTPN22,即蛋白酪氨酸磷酸酶非受體型22,目前認為該基因編碼的淋巴酪氨酸磷酸酶可以影響T細胞活化,從而影響免疫穩(wěn)態(tài)而導致自身免疫病的發(fā)生。PADI4,即肽基精氨酸脫亞胺酶4,為編碼精氨酸轉化為瓜氨酸殘基的酶家族的成員,可在粒細胞和巨噬細胞介導的炎癥和免疫反應中發(fā)揮作用,因而可能與類風濕關節(jié)炎的發(fā)病相關。PADI4是一種翻譯后修飾酶,可以在鈣離子存在的情況下把精氨酸殘基轉化成瓜氨酸殘基,此過程稱作瓜氨酸化。PADI4與類風濕性關節(jié)炎最密切相關,哺乳動物的PAD受細胞內的鈣濃度、自動瓜氨酸化和二聚化的調控蛋白質瓜氨酸化的改變可能可以解釋類風濕性關節(jié)炎的風險因素,有研究猜測,PTPN22R620可能與PADI4相互作用,從而限制了瓜氨酸化以及中性粒細胞胞外殺菌網(wǎng)絡的形成。PTPN22R620是天然的PADI4的抑制劑,但是PTPN22W620完全剝奪了PTPN22對PADI4的抑制作用導致高度瓜氨酸化。而目前對于PTPN22和PADI4的相互作用依然不是很清晰,其中主要的限制因素是難以得到大量、均一度高的PTPN22和PADI4蛋白,從而造成其數(shù)據(jù)的缺乏。本論文針對這一難題,探索了PTPN22和PADI4在大腸桿菌這一原核表達系統(tǒng)中的表達,并對二者相互作用關系進行了研究。通過優(yōu)化大腸桿菌的培養(yǎng)溫度、培養(yǎng)時間和培養(yǎng)濃度,明顯改善了蛋白的表達量、行為及純度。通過親和層析、離子交換層析、凝膠過濾色譜層析等方法提高了蛋白純度,最終能夠在體外得到具有較高濃度、較高純度的、行為較為均一的PTPN22和PADI4蛋白。然而,個別PTPN22重組蛋白和PADI4蛋白可以實現(xiàn)共表達,純化得到的PTPN22和PADI4蛋白之間并不存在相互作用。本研究加深了我們對于PTPN22和PADI4蛋白的整體認識,為將來的結構解析以及臨床應用奠定了良好的基礎。
[Abstract]:Rheumatoid arthritis is a common, chronic, autoimmune disorder.It is found that the main features of the disease are inflammation of joints and bones, necrosis of joints and erosion of bones, which will eventually lead to deformity and loss of function of joints.The etiology of rheumatoid arthritis is unclear. PTPN22, a protein tyrosine phosphatase non-recipient 22, is now thought to affect the activation of T cells by the lymphotyrosine phosphatase encoded by the gene.This affects the immune homeostasis and leads to the occurrence of autoimmune disease. PADI4, which is a member of the enzyme family that encodes arginine to citrullinate residue, is called peptidyl arginine deiminase 4.May play a role in inflammatory and immune responses mediated by granulocytes and macrophages, and may therefore be associated with the pathogenesis of rheumatoid arthritis. PADI4 is a post-translational modifier.Arginine residues can be converted into citrulline residues in the presence of calcium ions, a process called melamine acidification. PADI4 is most closely related to rheumatoid arthritis, and PAD in mammals receives intracellular calcium concentrations.Changes in melamine and dimeric regulation proteins may explain the risk factors of rheumatoid arthritis, and some studies suggest that PTPN 22R620 may interact with PADI4.PTPN22R620 is a natural inhibitor of PADI4, but PTPN22W620 completely deprives the inhibition of PADI4 by PTPN22.However, the interaction between PTPN22 and PADI4 is still not clear, and the main limiting factor is that it is difficult to obtain a large number of PTPN22 and PADI4 proteins, which are once high, resulting in a lack of data.In this paper, the expression of PTPN22 and PADI4 in E. coli prokaryotic expression system was investigated, and the interaction between them was studied.By optimizing the culture temperature, time and concentration of Escherichia coli, the expression, behavior and purity of protein were significantly improved.The protein purity was improved by affinity chromatography, ion exchange chromatography and gel filtration chromatography, and PTPN22 and PADI4 proteins with high concentration and high purity could be obtained in vitro.However, individual PTPN22 recombinant protein and PADI4 protein can be coexpressed, and there is no interaction between purified PTPN22 and PADI4 protein.This study has deepened our overall understanding of PTPN22 and PADI4 proteins and laid a good foundation for future structural analysis and clinical application.
【學位授予單位】:哈爾濱工業(yè)大學
【學位級別】:碩士
【學位授予年份】:2015
【分類號】:R593.22
【參考文獻】
相關期刊論文 前2條
1 鐘兵;方勇飛;李華;萬萍;楊菲;王勇;;PADI4基因多態(tài)性與類風濕關節(jié)炎的相關性研究[J];第三軍醫(yī)大學學報;2010年11期
2 孫濤;李焱;李向東;孟慶松;;類風濕性關節(jié)炎滑膜組織PADI4的表達[J];國際檢驗醫(yī)學雜志;2012年16期
,本文編號:1756869
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