吸虫CD59样蛋白质的生物信息学分析

Bioinformatic analysis of newly identified CD59-like proteins in trematodes

目的对在寄生虫中新发现的CD59样蛋白序列进行生物信息学分析,为研究其功能奠定基础。方法应用生物信息学方法,从不同的数据库中查找6种吸虫(肝片吸虫、大片吸虫、日本血吸虫、曼氏血吸虫、华支睾吸虫、麝猫后睾吸虫)的CD59样蛋白序列,应用生物信息学软件对获得的序列进行信号肽和GPI锚定蛋白的预测和分析,应用Clustlw与人CD59序列进行比对分析,并应用Mrbayes构建进化树。结果 6种吸虫分别存在5-11种不同的CD59样蛋白,大小98~137aa,富含半胱氨酸,均有LY6/CD59蛋白质家族的保守膜体"CCXXXXCN"。与人CD59比对,在10个半胱氨酸中有8个相互匹配。根据6种吸虫中获得的46条CD59样蛋白的氨基酸序列构建系统进化树,可将吸虫分为6个不同的大群,其中有3个群均包含裂体科、片形科和后睾科吸虫序列,另外3个为裂体科、片形科和后睾科吸虫各自独立成群。结论吸虫中存在一类CD59样蛋白家族,这类蛋白质与人CD59有类似的结构,进化分析提示该类蛋白质功能具有多样性。

Objective To sequence and bioinformatically analyze novel CD59-like proteins in trematodes in order to provide a basis for the future study of their function. Methods Different databases were searched for sequences of CD59-like proteins of Fasciola hepatica, Fasciola gigantica , Schistosorna japonicum , Schistosoma rnansoni , Clonorchis sinensis, and Opisthorchis viverrini. Signal peptides and GPI-anchored proteins of the obtained sequences were predicted using bioinformatic software. Clustlw was used to align the obtained sequences with the sequence of human CD59, and MrBayes was used to create a phylogenic tree. Results Five to 11 CD59-like proteins were found in six species of trem- atodes. The proteins ranged in size from 98 to 137 aa. The mature protein contained 10 cysteines and a conserved LY6/ CD59 family motif of ＂CCXXXXCN. ＂ Phylogenic analysis indicated that the amino acid sequences of 46 CD59-like pro- teins from the six species of trematodes were clustered into 6 different clades. Three of these clades included sequences of CD59-like proteins from Schistosoznatidae, Fasciolidae, and Opisthorchiidae, and the other three clades consisted of se- quences of CD59-like proteins that were individually unique to Schistosomatidae, Fasciolidae, and Opisthorchiidae. Conclusion A family of CD59-1ike proteins was found in flukes, and this family is structurally similar to human CD59. Phylogenic tree analysis suggested that these proteins have varied functions.