重要翻译后修饰物多聚SUMO蛋白的化学合成研究

发布时间：2018-04-15 21:34

本文选题：蛋白质化学合成 + 自然化学连接　；参考：《合肥工业大学》2017年硕士论文

【摘要】：随着人类基因组计划的完结,蛋白质结构与功能的关系成为当前生物学研究的热点。其中,蛋白质的翻译后修饰受到科研人员的广泛关注(如甲基化,磷酸化,泛素化和类泛素化等)。这些翻译后修饰蛋白在生物体内发挥着重要的生理功能。SUMO蛋白是一种类泛素蛋白,它可以通过E1,E2,E3三级酶联反应共价偶联到某些底物蛋白上,形成SUMO修饰的目标蛋白,而SUMO化蛋白在生物体内的核质转运、信号传导、DNA的损伤修复和蛋白质的降解等过程中发挥着重要的作用。在SUMO化的过程中,SUMO蛋白本身也可以被乙酰化或者多聚化,SUMO蛋白本身的这种修饰对SUMO化蛋白的功能发挥同样具有重要的作用。为了对乙酰化SUMO和多聚SUMO蛋白在SUMO化修饰过程中的功能作进一步研究,获得性质均一的乙酰化SUMO和多聚SUMO蛋白是相关研究得以进行的关键。由于传统生物表达的方法只能获得由天然氨基酸组成的蛋白质,而类似乙酰化或者多聚化这种翻译后修饰蛋白往往很难获得。蛋白质化学合成技术凭借其能够在原子尺度精准构筑蛋白质的优势,是获得这些翻译后修饰蛋白非常有效的一种手段。其中,Liu课题组将酰肼作为C端硫酯的掩蔽基团,简化了肽片段连接中C端硫酯的合成问题,具有操作简单,效率高的优点。本文作者运用基于多肽酰肼连接的蛋白质化学合成策略应用于SUMO-2蛋白,乙酰化SUMO蛋白,D型SUMO蛋白和二聚SUMO蛋白的化学合成中,实现了两片段SUMO-2,乙酰化SUMO-2,D型SUMO以及四片段二聚SUMO蛋白的化学全合成,并通过生化实验验证了合成蛋白的正确性。本工作为进一步化学合成的多聚泛素、多聚类泛素蛋白提供了一种普适性方法,进而阐明蛋白质类泛素化特异性合成、识别、降解过程的生物化学机制的研究提供了有效的工具。
[Abstract]:With the completion of the Human Genome Project, the relationship between protein structure and function has become a hot topic in biological research.Among them, post-translational modification of proteins has attracted extensive attention (such as methylation, phosphorylation, ubiquitin and ubiquitin).These posttranslational modified proteins play an important physiological function in vivo. Sumo protein is a Ubiquitin protein, which can be covalently coupled to some substrate proteins by E1OE2E3 tertiary enzyme-linked reaction to form the target protein modified by SUMO.However, SUMO proteins play an important role in the processes of nuclear and cytoplasmic transport, signal transduction, damage repair and protein degradation.In the process of SUMO, Sumo protein itself can also be modified by acetylation or polymerylation. This modification also plays an important role in the function of SUMO protein.In order to further study the functions of acetylated SUMO and poly (SUMO) proteins in the process of SUMO modification, uniform acetylated SUMO and poly (SUMO) proteins are the key to the study.Because traditional biological expression methods can only obtain proteins composed of natural amino acids, post-translational modified proteins such as acetylation or polymerization are often difficult to obtain.Protein chemosynthesis is an effective way to obtain these post-translational modified proteins because of its advantage of precisely constructing proteins on atomic scale.Liu group used hydrazide as the masking group of C-terminal thioester, which simplifies the synthesis of C-terminal thioester in peptide fragment connection, and has the advantages of simple operation and high efficiency.In this paper, the authors used the protein chemical synthesis strategy based on polypeptide hydrazide binding in the chemical synthesis of SUMO-2 protein, acetylated SUMO protein D type SUMO protein and dimer SUMO protein.The chemical synthesis of two fragments SUMO-2, acetylated SUMO-2 D type SUMO and four fragments dimeric SUMO protein was realized, and the correctness of the synthesized protein was verified by biochemical experiments.This work provides a universal method for the further chemical synthesis of polyubiquitin, polyubiquitin protein, and further elucidates the specific synthesis and recognition of protein ubiquitin.The study of biochemistry mechanism of degradation process provides an effective tool.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O629.73

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