CD200蛋白质分子三维结构的构建

发布时间：2018-01-14 16:39

本文关键词：CD200蛋白质分子三维结构的构建　出处：《吉林大学》2008年硕士论文　论文类型：学位论文

【摘要】： CD200分子是自1979年由Mc Master发现的。它属于免疫球蛋白超家族,是一种I-型膜糖蛋白,胞膜外区有两个免疫球蛋白样结构域。CD200在人类和啮齿类动物均有表达,广泛分布在中枢和外周神经系统、胸腺细胞、淋巴细胞、血管内皮细胞、平滑肌细胞以及卵巢细胞和神经元。具有介导T细胞共刺激信号,促进T细胞增殖,使1型细胞因子减少,2型细胞因子增加的作用,从而发挥诱导同种和异种的移植耐受,延长移植物存活时间的功能。CD200胞内仅有19个氮基酸,缺乏任何信号序列,也没有作为信号衔接蛋白相互作用所需的跨膜锚定位点,因此其功能效应需要表达于其他细胞表面相应的受体参与。CD200与CD200Rs结合后,通过胞内NPXY序列或跨膜区与信号衔接分子结合产生效应,但其分子机制不明。蛋白质的功能主要取决于它们的三维结构、运动及相互作用。对蛋白质结构的解析可以从根本上阐明蛋白质功能的分子机制和基础,同时也是研究蛋白质功能的一个重途径。本研究利用同源模建的方法对CD200分子进行了蛋白质三维结构预测的理论研究。主要结果:通过同源模建和分子动力学模拟,得到了CD200的三维结构。研究表明CD200分子在化学结构上是对称的。为CD200在前期的实验提供了理论依据。结论:通过从蛋白质三维结构预测的理论研究中,获得了CD200分子的一个对称的分子结构蛋白质三维构象。从理论基础上为CD200分子的功能及作用提供了有力依据。
[Abstract]:The CD200 molecule was discovered by MC Master in 1979. It belongs to the immunoglobulin superfamily and is an I- type membrane glycoprotein. There are two immunoglobulin-like domains. CD200 is expressed in human and rodent. It is widely distributed in the central and peripheral nervous system, thymocytes, lymphocytes, vascular endothelial cells. Smooth muscle cells, ovarian cells and neurons can mediate T cell costimulatory signal, promote T cell proliferation, and make type 1 cytokines decrease the increase of type 2 cytokines. Thus, the function of inducing allogeneic and xenogeneic transplantation tolerance, prolonging the survival time of the graft. CD200 has only 19 azo acids in the cell, and lacks any signal sequence. There is no transmembrane anchoring site required for the interaction of signal junction proteins, so its functional effects need to be expressed in the corresponding receptors on the surface of other cells involved in the binding of. CD200 to CD200Rs. The molecular mechanism of NPXY sequence or transmembrane region binding to signal junction molecules is unclear. The function of protein mainly depends on their three-dimensional structure, movement and interaction. The analysis of protein structure can explain the molecular mechanism and basis of protein function. At the same time, it is also a important way to study the function of protein. In this study, we used the homology modeling method to predict the three-dimensional structure of CD200 molecule. Main results: the molecular dynamics simulation of homologous modeling was carried out. The three-dimensional structure of CD200 is obtained. The results show that the chemical structure of CD200 is symmetrical, which provides a theoretical basis for the previous experiments of CD200. Conclusion: from the theoretical study of protein three-dimensional structure prediction. The three-dimensional conformation of a symmetric molecular structure protein of CD200 molecule has been obtained, which provides a powerful basis for the function and action of CD200 molecule on the basis of theory.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R392.11

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