In order to make clear the protein compositions of Sipunculus nudus and investigate its immune-related proteins, proteomic analysis was performed on body wall and coelomic fluid of Sipunculus nudus. A total of 1659 proteins were identified, and 539 proteins were differentially expressed in the coelomic fluid compared to those in the body wall, of which 415 proteins were up-regulated while 124 proteins were down-regulated. Gene Ontology (GO) analysis showed that the GO terms involved in the two parts of Sipunculus nudus were similar, with metabolic processes, catalytic activity and cell occupying the top categories of biological process, molecular function and cellular component, respectively. KEGG pathway analysis showed that 49 pathways in body wall and 48 in coelomic fluid were mapped respectively, and these pathways were mainly related to cellular processes, environmental information processing, genetic information processing and metabolism. The COG analysis showed that 757 proteins from body wall and 889 from coelomic fluid were classified into 26 COG categories, respectively. Pfam annotation revealed the mainly immune-related proteins contained in Sipunculus nudus, such as insulin-like growth factor binding protein, catalase, basement membrane proteoglycan, titin. Our research provides the first proteomic information of Sipunculus nudus, which contributes to the study of functional proteins in Sipunculus nudus and is of great significance for the application of Sipunculus nudus in functional foods and medicines.

为了使清除蛋白组合方格星虫，探讨其免疫相关蛋白，在体壁和体腔液进行蛋白质组学分析方格星虫。鉴定出总共1659种蛋白质，与体壁蛋白质相比，在体液中有539种蛋白质差异表达，其中415种蛋白质被上调，而124种蛋白质被下调。基因本体论（GO）分析表明，GO术语参与了Sipunculus nudus的两个部分相似，代谢过程，催化活性和细胞分别占据生物过程，分子功能和细胞成分的顶级类别。KEGG通路分析显示，分别绘制了体壁中的49条通路和粘液中的48条通路，这些通路主要与细胞过程，环境信息处理，遗传信息处理和代谢有关。COG分析表明，来自体壁的757种蛋白质和来自腔液的889种蛋白质分别被分为26种COG。Pfam注释揭示了莲子中含有的主要与免疫有关的蛋白质如胰岛素样生长因子结合蛋白，过氧化氢酶，基底膜蛋白聚糖，肌动蛋白。我们的研究提供了第一至蛋白质组学信息方格星虫，这有助于在功能蛋白的研究方格星虫，是对应用具有重要意义方格星虫功能食品和药品。