基于生物信息学的人P2X7R结构分析及功能预测

Structure analysis and function prediction of human P2X7R based on bioinformatics

目的:利用生物信息学分析人嘌呤能离子通道型受体7(purinergic ligand-gated ion channel 7 receptor,P2X7R)蛋白结构特征,同时对不同物种的P2X7R蛋白同源性、蛋白质间的相互作用、细胞抗原表位进行预测,为相关疾病诊断与治疗提供理论依据。方法:登录ProtParam、TMHMM、ProtScale及SignalP 5.0 Server等软件对人P2X7R蛋白进行分析预测。结果:人P2X7R蛋白由595个氨基酸组成,分子式为C_(3077) H_(4749) N_(835) O_(871) S_(40,)理论等电点PI为8.62,不稳定系数46.07,总平均亲水性为−0.317;该蛋白为亲水性蛋白,无信号肽同时存在跨膜区,属于跨膜蛋白;二级结构中存在157个α-螺旋,288个无规卷曲,分别占所有氨基酸比例26.39%、48.40%,三级结构预测结果的覆盖率为100%,序列相似度为80.34%,同时拉曼图结果分析该预测结构较为稳定;蛋白相互作用结果显示,存在多种与人P2X7R蛋白相互作用的蛋白,且P2X7R与炎症发生密切相关;该蛋白存在多个B、T细胞抗原表位,可为疫苗的研制提供思路。结论:基于生物信息学方法得到的人P2X7R蛋白分析具有一定可靠性,P2X7R参与炎症疾病的发生发展,通过预测筛选出的B、Th、CTL细胞抗原表位将为疾病的治疗提供方案。

Objective:To analyze the structural features of human P2X7R protein and predict homology,protein-protein interaction,and cell epitope based on bioinformatics method to provide theoretical basis for the diagnosis and treatment of related diseases.Methods:Human P2X7R protein was analyzed and predicted by ProtParam,TMHMM,ProtScale and SignalP 5.0 Server,etc.Results:Human P2X7R protein was composed of 595 amino acids.The molecular formula was C_(3077) H_(4749) N_(835) O_(871) S_(0) with the theoretical isoelectric point PI of 8.62.The instability coefficient was 46.07 and the total average hydrophilicity was−0.317.The protein was a hydrophilic protein without signal peptid,but with transmembrane region,and belonged to transmembrane pro-teins.There were 157αhelices and 288 random coils in the secondary structure of human P2X7R protein,accounting for 26.39%and 48.40%of all amino acids.The coverage rate of prediction of the three-level structure was 100%,and the sequence similarity was 80.34%.The ramachandran plot showed that the predicted structure was relatively stable.The interaction of proteins showed that there were a variety of proteins interacting with human P2X7R,and P2X7R was closely related to inflammation.This protein had many epitopes of B and T cell,which could provide ideas for vaccine development.Conclusion:The analysis of human P2X7R protein based on bioinformatics method is reliable to some extent.P2X7R is involved in the development of inflammatory diseases,and the screened antigenic epitope of B,Th and CTL cells by prediction will provide treatment schemes for diseases.