人乳头瘤病毒衣壳蛋白特异性多肽与细胞受体的结合机制研究

发布时间：2018-06-23 07:07

本文选题：多肽 + 肝素　；参考：《吉林大学》2011年博士论文

【摘要】：人乳头瘤病毒(HPV)是一类嗜上皮性无囊膜双链DNA病毒,迄今已在人体皮肤及黏膜组织中分离出100多种不同型别。病毒的生命周期以感染细胞为起点,因此研究病毒的感染机制是了解和控制病毒的重要基础,已有的研究表明HPV衣壳蛋白中的碱性氨基酸区域和细胞表面硫酸乙酰肝素蛋白聚糖(HSPG)受体之间存在特异性相互作用。我们设计合成了一系列潜在的结合细胞受体的靶点多肽,利用ITC、NMR、SLS、FL及CD等实验检测了它们与细胞表面受体模拟物肝素之间的相互作用,并对相关作用机制进行了系统研究。主要内容包括： (一)、设计合成了HPV-16衣壳蛋白的五个多肽模拟物,检测了它们与肝素之间的识别及相互作用。实验结果表明：多肽结合肝素不仅受多肽本身氨基酸残基种类和数目影响,而且存在明显的序列特异性依赖现象,除最基本的静电作用在内,疏水作用和氢键作用等也都参与了这些多肽与肝素的结合。另外,除了L1蛋白,L2在HPV的感染过程中也参与了结合细胞表面受体,同时证实硫酸乙酰肝素蛋白聚糖确实是细胞结合HPV的主要受体。 (二)、设计合成了HPV-16和HPV-18L1的C端相对应位置的14肽,比较这两个多肽结合肝素的差别。结果表明,尽管H16Ctb和H18Ctb两个多肽所含的氨基酸种类与个数比较接近,但是因为氨基酸残基排列顺序的不同,导致在与肝素结合时,二者在结合能力与分子机制方面都有很大的差别。 (三)、分别设计合成了具有不同感染性质的八种型别HPV的L1蛋白C端多肽,同样利用ITC和SLS等方法研究了这些多肽与肝素的结合过程,确认了它们是病毒结合细胞受体的靶点,比较了它们在结合宿主细胞受体方面的差别。综上所述,我们利用物理化学实验方法研究了HPV衣壳蛋白特异性多肽与肝素之间的相互作用,定量证实了衣壳蛋白的富含碱性氨基酸区域与细胞表面硫酸乙酰肝素蛋白聚糖在病毒感染细胞中的重要作用,研究了它们之间的作用机制,在此基础上为不同型别的不同感染性质提出一种可能的解释。
[Abstract]:Human papillomavirus (HPV) is a kind of epitheliophilic double-stranded DNA virus. Up to now, more than 100 different types of HPV have been isolated from human skin and mucosal tissues. The life cycle of a virus begins with infected cells, so studying the mechanism of virus infection is an important basis for understanding and controlling viruses. Studies have shown that there is a specific interaction between the basic amino acid region of HPV capsid protein and the heparin sulfate proteoglycan (HSPG) receptor on the cell surface. We have designed and synthesized a series of potential peptides targeting cell receptors. The interaction between these peptides and heparin, a cell surface receptor mimic, was investigated by ITCNMR-SLSS-FL and CD experiments, and the mechanism of the interaction was systematically studied. The main contents are as follows: (1) five peptide simulants of HPV-16 capsid protein were designed and synthesized, and their recognition and interaction with heparin were detected. The results showed that the peptide binding heparin was not only affected by the amino acid residues and the number of amino acids, but also had a sequence specific dependence, except for the most basic electrostatic action. Hydrophobic and hydrogen bonding are also involved in the binding of these peptides to heparin. In addition, L1 protein L2 is involved in the binding cell surface receptor in the process of HPV infection, and it is confirmed that heparin sulfate proteoglycan is the main receptor of cell binding HPV. (2) 14 peptides corresponding to C-terminal of HPV-16 and HPV-18L1 were designed and synthesized, and the difference of heparin binding between HPV-16 and HPV-18L1 was compared. The results showed that although the amino acids of H16Ctb and H18Ctb were similar to each other, the amino acid residues of H16Ctb and H18Ctb were different in order, which led to the binding with heparin. There are great differences in binding ability and molecular mechanism between them. (3) eight C-terminal peptides of L1 protein with different infection properties were designed and synthesized respectively. The binding process of these peptides to heparin was also studied by using ITC and SLS methods, which confirmed that they were the target of viral binding cell receptor. Their differences in binding to host cell receptors were compared. In conclusion, we studied the interaction between HPV capsid protein specific polypeptide and heparin by physical and chemical methods. The important role of heparin sulfate proteoglycan on the surface of capsid protein, which is rich in basic amino acids, was quantitatively confirmed, and the mechanism between them was studied. On this basis, a possible explanation for different types of infection properties is proposed.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2011
【分类号】：R373

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