人SEPT 9蛋白序列特性和结构建模研究.docVIP

人SEPT 9蛋白序列特性和结构建模研究 摘 要：SEPT9蛋白广泛存在于真核生物中，属于septin超家族成员，在细胞分裂、胞内物质运输和感染的发生、治疗、痊愈等过程发挥着重要作用，并且SEPT9蛋白与人类的一些疾病如脑肿瘤、结直肠癌、乳腺癌、等恶性肿瘤以及Parkison疾病、Alzheimer病等神经系统退行性疾病的发生相关。本论文利用生物信息学方法，对人septin9亚家族8条蛋白序列进行了多序列比对，将其分成了3类蛋白，并对SEPT9蛋白的基本理化性质、结构进行了分析、同时对其模建结果进行质量评价和活性位点进分析。结果表明，人SEPT9蛋白亚家族成员，序列长度和氨基酸组成差异较小，均为不稳定的球形蛋白，无跨膜区和信号肽；二级结构均以alpha;-螺旋和无规则卷曲为主，其中人SEPT9蛋白(XP-006721706.1）的三级结构得到模建，Ramachandran 图检测表明此模型结构符合立体化学规则，经预测该蛋白配基结合位点有多个，位点102可能是该蛋白的活性位点。9798 关键词：人；SEPT 9蛋白；模建；活性位点；生物信息学 The Study of sequence characters and homology modeling of human SEPT 9 protein Abstract: SEPT9 protein widely exists in eukaryotic organism , members of the septin superfamily, GTP-binding protein, which is related to cell pision cycle. SEPT9 protein plays an important role in many aspects such as cell pision, material transportation and human diseases, such as brain tumors, colorectal cancer, breast cancer as well as nervous system degenerative diseases such as Parkison disease and Alzheimer#39;s disease. In this paper, SEPT9 proteins were classified into three classes on the bases of analysis on multiple sequence alignment by using bioinformatics methods. And physical and chemical properties, structures, the evaluation of its tertiary structure results, active site are analyzed and predicted. The results show that the structure of SEPT9 protein and its family members is conservative, they have smaller difference in amio acid composition and sequence length ,globular proteins are unstable,no transmembrane and signal peptide; Secondary structure is given priority to alpha helix and random coil. The tertiary structure of SEPT9 protein (XP_006721706.1) was gotten, which meets the rule of stereochemistry in the figure of Ramachandran, There are lots of ligands binding sites ,102 sites may be the active site of the protein. 致谢21 人SEPT9蛋白序列特性和结构建模研究引 言 Steptin基因家族广泛存在于真菌[1]、线虫[2]、果蝇[3.4]、爪蟾[5]及哺乳动物[6]等绝大多数真核生物中，在原生生物和植物中尚未检测到它的存在。研究[7] 表明，酵母、线虫和果蝇中分别存在7种、2种和5种septin基因，人基因组中至少存在9～10种。septin基因亚家