Screening and bioinformatic analysis of trehalase in Thelazia callipaeda / 中国血吸虫病防治杂志

Objective To characterize the trehalase gene in Thelazia callipaeda through screening the annotated data of the T. callipaeda genome, and to investigate the biological characteristics of the trehalase gene-coding protein. Methods The trehalase gene was screened from the T. callipaeda genome and subjected to validation by using a PCR assay. The structural features of the coding protein were analyzed with bioinformatics tools, including hydrophobicity, transmembrane region, signal peptides, conserved domains, as well as the secondary and tertiary structures and the antigen epitope. Homology analysis of the amino acid sequences was performed, and the phylogenetic tree was built by the MEGA X software. In addition, the protein-protein interaction network was deduced from the STRING database. Results The sequence of the trehalase gene with the complete CDS region was obtained from T. callipaeda genome, which had a length of 1 638 bp and encoded 545 amino acids. The encoded protein was predicted to have a molecular weight of 63 478.48 ku and be a secretory protein. The 5′ domain of the encoded protein contained a signal peptide without transmembrane regions, and was predicted to contain 7 antigen epitopes. Based on the protein-protein interaction network of nematodes in the STRING database, the protein-protein interaction network of the trehalase gene of T. callipaeda was deduced, and 27 interactions covering 10 genes were identified. Conclusions A trehalase gene is successfully identified in T. callipaeda genome and its coding protein receives a bioinformatics analysis, which provides insights into the research on the biological functions of the protein and the screening of vaccine candidates for thelaziasis callipaeda.

Prediction and analysis for secretory proteins from Thelazia callipaeda at Genome Scale / 中国人兽共患病学报

We conducted prediction and analysis for secretory proteins from Thelazia callipaeda at Genome Scale based on the previous full genome annotation.The software SignalP,TMHMM,big-PI Predictor,MEME,Protcomp and SecretomeP were combined to process the prediction of the secretome of Thelazia callipaeda.The analyses of secretory proteins by GO function enrichment,KEGG pathway,and statistics of domains were performed.Results showed that totally 259 secretory proteins were found in Thelazia callipaeda genome and the amino acid lengths of secretory proteins were mainly concentrated between 100 to 700 aa exclusively.GO function analysis of secretory proteins indicated that they were enriched in the secreting pathways and in the interactions with host.The results of KEGG metabolism secretory proteins suggested that some of them contributed to drug metabolism and glutathione metabolism.And domain analysis suggested that most of them were glycoside hydrolase,contributing to sugar metabolism.Around 126 secretory proteins had antigenicity of B-cell epitope.In summary,we found that secretory proteins in Thelazia callipaeda were most small proteins,which were involved in sugar metabolism and antioxidative activity,facilitating Thelazia callipaeda to invade the hosts and play a key role in the parasitic course.