中文摘要：

目的对赤子爱胜蚓Eisenstasin样蛋白cDNA序列和氨基酸序列进行综合分析，为其结构和功能的研究奠定理论基础。方法从赤子爱胜蚓cDNA文库中随机测序获得目标cDNA序列，利用基因和蛋白质分析处理软件DNAMAN、NCBIORFfinder、BLAST、ConservedDomains、GOR、SWISS—MODEL等软件对该目标的基因序列和氨基酸序列进行综合分析。结果测序获得的赤子爱胜蚓Eisenstasin样蛋白cDNA序列长为565bp，编码148个氨基酸残基，基因序列比对显示该蛋白与Eis—enstasinImRNA的编码序列同源度最高，两者核苷酸的相似度为78％（148／190），氨基酸序列比对显示该蛋白与EisenstasinⅡ的氨基酸序列同源度最高，两者氨基酸的相似度为37％（61／166），目标序列中存在3段Antistasin家族保守结构域，二级结构和三级结构预测显示目标蛋白中主要存在B折叠和无规卷曲的结构，与Antistasin的预测结果高度相似。结论经多种生物软件分析，可以认为本次发现的Eisenstasin样蛋白与安德爱胜蚓组织中发现的Eisenstasin和水蛭中发现的Antistasin同源度高，可能具有抗凝功能。

英文摘要：

Objective To conduct a comprehensive analysis of cDNA sequence and amino acid sequence of Eisenstasin-like protein from Eisenia foetida for laying a theoretical foundation for the research on the structure and function of the protein. Methods Target cDNA sequence was got from Eisenia foetida cDNA library by random sequencing, and the sequences were analyzed using gene and pro- tein analysis and processing software DNAMAN,NCBI ORF finder,BLAST,Conserved Domains,GOR,SWISS-MODEL. Results The length of cDNA sequence of Eisenstasin-like protein was 565 bp, encoding 148 amino acid residues. Gene sequence alignment showed that the homology between the coding sequence of the target protein and Eisenstasin I mRNA was the highest, and the similarity be- tween the two nucleotide sequences was 78% （148/190）. The amino acid sequence alignment showed that the homology between the amino acid sequence of the target protein and Eisenstasin ]I was the highest, and the similarity between the two amino acid sequences was 37% （61/166）. The target sequence showed three Antistasin family conserved domains, secondary and tertiary structure prediction showed that there were mainly ~ folding and random coil in the target protein, which was highly similar to the prediction results of An- tistasin. Conclusion The various biological software analysis suggest that the homologous degree between Eisenstasin-like protein from Eisenia foetida and Eisenstasin from earthworm Eisenia andrei and Antistasin from leech is high, and this Eisenstasin-like protein may have the function of anticoagulation.