乳腺癌相关基因环氧化酶2(COX-2)编码蛋白的主要特性与抗原表位生物信息学分析

Bioinformatics analysis of the main characteristics and epitopes of the gene encoding COX-2 protein from breast cancer

目的:通过生物信息学分析人乳腺癌相关基因环氧化酶2(Cycloxygenase 2,COX-2)编码蛋白的主要特性与抗原表位,筛选该蛋白的T/B细胞联合表位。方法:利用蛋白分析专家系统(ExPASy)提供的Prot-Param、SignalP、SOSUI、TMHMM、MotifScan,NCBI上的ORF finder、Bcepred、SYFPEITHI、NetCTL等生物信息学在线分析程序,结合Gene Runner、DNAMAN等生物信息学软件,分析、预测COX-2蛋白的理化性质、信号肽、可溶性、表面可及性、可塑性,跨膜区,翻译后修饰位点、亲(疏)水性、二级结构、T/B细胞抗原表位等。结果:该蛋白由604个氨基酸组成,分子式为C3126H4787N823O883S28,分子质量单位为68.924 kDa,等电点理论值为7.27,波长280 nm时的吸光度(A)值为1.073,半衰期为30 h,有7个表面可及性参数≥1.9的区域、4个亲水性参数得分≥1.9的区域、3个柔韧性参数得分≥2的区域、26个翻译后修饰位点、23个潜在B细胞表位、3个CTL表位和辅助性T细胞联合表位、2个T/B细胞联合表位,为可溶性表达蛋白。结论:人乳腺癌相关抗原COX-2基因编码的COX-2蛋白为可溶性表达蛋白,2个T/B细胞联合表位,可作为乳腺癌免疫学治疗的重要靶点。

Objective：To predict the main characteristics of the COX -2 protein from human breast cancer enco ding by COX - 2 gene and its T/B cell epitopes by bioinfoimatics. Methods ： The physico - chemical property, solubil-ity, surface accessibility, flexibility, post - translational modification sites, signal peptide, transmembrane domain, hy-drophilicity/hydrophobicity, secondary structure and T/B cell epitopes of COX -2 protein were analyzed and predic-ted by using the bioinformatics tools - ExPASy, including ProtParam, SOSUI, TMHMM, MotifScan, ORF finder, Sig-nalP, and Beepred, combined with bioinformatics softwares （ Gene Runner, DNAMAN, etc）. Results ： COX - 2 protein consisted of 604 amino acids with listed characters：the molecular formula, C3126H4787N8230883S28 ; the molecular mass,68. 924 kDa ; the value of theoretical isoelectric point,7.27 ; the absorbance （A） value, 1. 073 （280 nm） ; half -life was 30 hr. There were 7 zones with surface accessibility ≥ 1.9,4 zones with hydrophilicity ≥ 1.9,3 zones with flexibility ≥2,26 post - translational modification sites ,23 potential B cell epitopes ,three T cell epitopes and two con-junctive cell epitopes as soluble protein expression. Conclusion：The COX -2 protein encoding by COX-2 gene can be used for breast cancer immunology therapy because of its soluble protein expression and conjunctive cell epitopes.