Characterization for secreted egg proteins associate with development of post schistosomal fibrosis.

在分离膜结合蛋白和分泌蛋白作为日本血吸虫疫苗靶点的同时，我们发现了一个由基因复制机制产生的具有潜在功能的新基因家族。本研究将结构同源性建模和生化方法相结合，发现该基因家族编码具有血红素结合特性的海胆精子蛋白、肠激酶和agrin （SEA）结构域的蛋白。典型的sea结构域，表征的蛋白质与糖胺聚糖特异性相互作用，与配体聚集和免疫逃避有关。与模拟的血红素结合口袋一致，我们观察到六配位血红素铁具有高亲和力的血红素结合和光谱特性。原生基因产物定位于成虫被皮和胃真皮（宿主血红素隔离和获取的界面），表明该基因家族在血红素解毒和血红素铁摄取中可能发挥作用。

While isolating membrane-bound and secreted proteins as targets for Schistosoma japonicum vaccine, we identified a novel potentially functional gene family which had originated by a gene duplication mechanism. Here, we integrated structural homology modeling and biochemical methods to show that this gene family encodes proteins with sea-urchin sperm protein, enterokinase and agrin (SEA)domain, with heme-binding properties. Typical of SEA-structural domains, the characterized proteins specifically interacted with glycosaminoglycans, with implication in ligand gathering and immune-evasion. Consistent with modeled heme-binding pocket, we observed high affinity heme-binding and spectroscopic attributes of hexa-coordinated heme iron. Localization of the native gene-products on adult worm tegument andgastrodermis, host interfaces for heme-sequestration and acquisition, suggests potential roles for this gene family in heme-detoxification and heme-iron uptake.