冈田绕眼果蝇丝氨酸蛋白酶抑制蛋白生物信息学分析

Bioinformatic analysis of an Amiota okadai serine protease inhibitor

目的运用生物信息学方法预测分析冈田绕眼果蝇丝氨酸蛋白酶抑制蛋白(serine protease inhibitor,Serpin)的结构与功能。方法基于冈田绕眼果蝇转录组数据分析,筛选出高差异表达的Serpin基因;利用在线软件TMHMM、ProtScale、Signal分别预测Serpin跨膜结构域、亲/疏水性、信号肽;运用NetPhos、SOPMA、SWISS-MODEL等工具预测Serpin潜在的磷酸化位点以及二、三级结构;利用MEGA5.0软件构建其系统进化树,通过STRING数据库对其互作蛋白网络进行预测,利用KEGG数据库对Serpin进行相关通路预测分析。结果从冈田绕眼果蝇转录组数据库中筛选出1条具有完整编码区的丝氨酸蛋白酶抑制蛋白序列,其基因全长1940 bp,开放阅读框为1344 bp,编码448个氨基酸;预测该基因编码蛋白相对分子质量约为49.28×10^5,为分泌蛋白;无信号肽,含有跨膜结构域,蛋白局部亲水性好,有潜在的磷酸化位点;二级结构分析显示,该蛋白无规则卷曲所占比例较高,为36.52%,三级结构所建模型准确可靠;系统进化分析显示,冈田绕眼果蝇Serpin与拟暗果蝇(Drosophila pseudoobscura)Serpin同源性100%,与黑腹果蝇(Drosophila melanogaster)Serpin同源性为73.8%,表明与上述果蝇亲缘关系较近。STRING数据库中鉴定出8种蛋白与Serpin具有相互作用,KEGG数据库显示13条与Serpin相关的信号通路。结论从冈田绕眼果蝇转录组数据库中筛选出1条丝氨酸蛋白酶抑制蛋白基因,生物信息学分析其编码蛋白为分泌蛋白,含有潜在的磷酸化位点,为该蛋白的生物学功能研究及冈田绕眼果蝇的防治研究奠定了基础。

Objective The structure and function of a serine protease inhibitor(Serpin)of Amiota okadai were predicted and analyzed bioinformatically.Methods Based on an analysis of transcriptome data on A.okadai,highly differentially expressed Serpin genes were screened.TMHMM,ProtScale and Signal were used to analyze Serpin for transmembrane domains,hydrophilicity/hydrophobicity,and signal peptides.NetPhos,SOPMA,and Swiss-model were used to analyze Serpin for potential phosphorylation sites and its secondary and tertiary structures.The software MEGA5.0 was used to construct a phylogenetic tree.The STRING database was used to predict protein networks and the KEGG database was used to analyze pathways for Serpin.Results A Serpin gene sequence with a complete coding region was selected from the transcriptomic database of A.okadai.The ORF of Serpin is 1,344 bp in length and it encodes a protein of 448 amino acids with a predicted molecular weight of about 49.28×10^5.The protein is a secretory protein.Serpin has a transmembrane domain and no signal peptides.The protein is hydrophilic and has potential phosphorylation sites.Analysis of the protein’s secondary structure indicated that random coils accounted for 36.52%,α-helices(Hh)accounted for 42.63%,β-folds(Ee)accounted for 15.18%,andβ-turns(Tt)accounted for 5.58%,and the tertiary structure indicated that the model was accurate and reliable.Phylogenetic analysis indicated that the Serpin sequence of A.okadai is 100%identical to Serpin from Drosophila pseudoobscura,91.1%similar to Serpin from D.guanche,and 73.8%similar to Serpin from D.melanogaster,so the genes are closely related.Eight proteins were found to interact with Serpin according to the STRING database,and the KEGG database yielded 13 Serpin-related signaling pathways.Conclusion A Serpin gene was screened from the A.okadai transcriptomic database,and bioinformatic analysis indicated that the encoded protein was a secretory protein that contained potential phosphorylation sites.These findings have laid the foundation for study of the biological function of this protein and the control of A.okadai.