基于抗原抗体相互作用的立体结构信息设计新型TNF-α拮抗分子

发布时间：2018-05-27 03:04

本文选题：TNF-α + 拮抗分子　；参考：《中国人民解放军军事医学科学院》2005年博士论文

【摘要】：TNF-α的过量表达与很多疾病密切相关,应用TNF-α的拮抗剂部分阻断这些疾病中的TNF-α水平,将成为一种有效的治疗措施。已开发的TNF-α拮抗剂主要包括两大类,即TNF受体与IgG的FC段形成的融合蛋白和抗TNF-α的单抗,国外已有成熟产品上市。开发具有自主知识产权的TNF-α拮抗分子具有重要的理论和实际意义。本论文拟根据构建的TNF-α与本实验室获得的鼠源功能性单抗Z12相互作用的复合物模型合理设计得到的低亲和力拮抗肽,借助建立的基于抗原—抗体相互作用结构信息设计抗体模拟物的技术平台,创造性地提出了三种提高TNF-α拮抗分子生物学活性的技术:(1)将设计的短肽通过Linker与人IgG1的FC段连接后构建成的免疫黏附分子(短肽—Linker-FC);(2)利用人抗体重链可变区(VH)的框架结构作为支架,同时展示三条短肽,设计成新型分子PTVH5;(3)优化TNF-α与Z12的复合物模型,设计活性提高的短肽。具体研究结果如下: (1)针对设计的TNF-α拮抗肽(PT1～PT4),选择抑制TNF-α细胞毒性效果最好的PT4,利用Linker将其与人IgG1的FC段连接,构建成PT4-Linker-FC融合蛋白,提高了PT4热力学稳定性。所构建的融合蛋白能够竞争抑制HRP标记的Z12与TNF-α的结合,能够明显抑制TNF-α介导的细胞毒效应,其抑制活性比单独的PT4有明显提高。 (2)考察能否利用人抗体可变区的框架结构作为支架,同时展示三个活性肽段。选择已设计的功能肽PT2、PT3和PT4,分别替换人抗体IgG重链可变区的三个CDR区,设计成抑制TNF-α的新型分子(命名为PTVH)。利用同源模建技术从
[Abstract]:The overexpression of TNF- 伪 is closely related to many diseases. The use of TNF- 伪 antagonist to partially block the level of TNF- 伪 in these diseases will be an effective treatment. The developed TNF- 伪 antagonists mainly include two categories: fusion protein formed by FC segment of TNF receptor and IgG and monoclonal antibody against TNF- 伪. It is of great theoretical and practical significance to develop TNF- 伪 antagonist molecules with independent intellectual property rights. In this paper, the low affinity antagonist peptide was designed according to the constructed complex model of TNF- 伪 interacting with mouse functional monoclonal antibody Z12. A technical platform for the design of antibody simulants based on the structure information of antigen-antibody interaction, Three techniques for enhancing the antagonistic molecular biological activity of TNF- 伪 were proposed in this paper: 1) Immunoadhesive molecules (short peptide-Linker-FCX _ 2) using the variable region of heavy chain of human antibody were constructed by connecting the designed short peptide with FC segment of human IgG1 through Linker. The frame structure acts as a scaffold, At the same time, three short peptides were designed to optimize the complex model of TNF- 伪 and Z12, and to design short peptides with improved activity. The specific findings are as follows: 1) for the designed TNF- 伪 antagonist peptide PT1, PT4 was selected to inhibit the cytotoxicity of TNF- 伪. The fusion protein of PT4-Linker-FC was constructed by ligating it with FC segment of human IgG1 by Linker, and the thermodynamics stability of PT4 was improved. The constructed fusion protein could competitively inhibit the binding of HRP labeled Z12 to TNF- 伪 and inhibit the cytotoxic effect mediated by TNF- 伪. The inhibitory activity of the fusion protein was significantly higher than that of PT4 alone. To investigate whether the frame structure of variable region of human antibody can be used as scaffold, and to display three active peptide segments at the same time. The designed functional peptides PT2, PT3 and PT4 were selected to replace the three CDR regions of the heavy chain variable region of human antibody IgG, respectively, and were designed as a novel molecule (named PTVHG) to inhibit TNF- 伪. Using the technology of homologous modeling
【学位授予单位】：中国人民解放军军事医学科学院
【学位级别】：博士
【学位授予年份】：2005
【分类号】：R392

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