华支睾吸虫组织蛋白酶D样天冬氨酸蛋白酶全长基因的生物信息学分析

目的从华支睾吸虫成虫全长cDNA质粒文库中识别组织蛋白酶D样天冬氨酸蛋白酶基因，利用生物信息学方法预测其结构和功能特征，为进一步的实验研究提供理论指导。方法利用生物信息学网站的在线分析工具和Vector NTI suite软件包，识别华支睾吸虫组织蛋白酶D样天冬氨酸蛋白酶基因，并预测其编码蛋白质的各种结构特征与功能特征，并根据该基因构建种系分子进化树。结果BLASTx分析该基因为全长基因，该基因全长1,459bp，编码425个氨基酸，具有两个天冬氨酸蛋白酶的催化位点。SignalP分析该基因编码的蛋白质含有信号肽序列，切割位点在第17和第18个氨基酸之间，分子进化树提示其与日本血吸虫组织蛋白酶D样天冬氨酸蛋白酶亲缘关系最近。结论组织蛋白酶D属于天冬氨酸蛋白酶家族，为分泌性蛋白，与日本血吸虫同源基因一致性最高，为后续实验筛选华支睾吸虫病的诊断抗原及药物靶标提供了必要的理论依据。

Bioinformatics Analysis of the Full-length Cathepsin D-like Aspartic Protease Gene from Clonorchis Sinensis

Objective With the help of the bioinformatics to predict the deduced protein＇ s structure and function, we identified cathepsin D - like aspartic protease from the full length eDNA plasmid library of Clonorchis sinensis in order to instruct the experiment. Methods The full - length Clonorchis sinensis cathepsin D - like Aspartic protease gene was identified from the Clonorohis sinensis full - length eDNA plasmid lihratory, and the corresponding structure and function of its deduced protein was predicted by the bioinformatics analyzing tools online and the complicated bioinformatics software package Vector NTI suite 8.0, meanwhile the molecular cladogram was reconstructed. Results The gene is comprised of 1 459 base pairs in the length, deduced 425 amino acids, contains a secretory signal peptide of 17 aa in the N terminus and is a complete full - length gene compared with the homologues in Gen bank. There are two aspartic active sites in the protein and the deduced protein was close to Cathepsin D - like aspartic protease from schistosoma japonicum in the molecular cladogram. Conclusion Cathepsin D - like Asparfic protease of Clonorchis sinensis belongs to the Aspartic protease superfamily and it is secretory protein, and may be potential to diagnose antigen and the drug target of the clonorchiasis.