The major hazard of arsenic in living organisms is increasingly being recognized. Marine mollusks are apt to accumulate high levels of arsenic, but knowledge related to arsenic detoxification in marine mollusks is still less than sufficient. In this study, arsenic bioaccumulation as well as the role of glutathione S-transferase omega (GSTΩ) in the process of detoxification were investigated in the Ruditapes philippinarum clam after waterborne exposure to As(III) or As(V) for 30 days. The results showed that the gills accumulated significantly higher arsenic levels than the digestive glands. Arsenobetaine (AsB) and dimethylarsenate (DMA) accounted for most of the arsenic found, and monomethylarsonate (MMA) can be quickly metabolized. A subcellular distribution analysis showed that most arsenic was in biologically detoxified metal fractions (including metal-rich granules and metallothionein-like proteins), indicating their important roles in protecting cells from arsenic toxicity. The relative mRNA expressions of two genes encoding GSTΩ were up-regulated after arsenic exposure, and the transcriptional responses were more sensitive to As(III) than As(V). The recombinant GSTΩs exhibited high activities at optimal conditions, especially at 37 °C and pH 4–5, with an As(V) concentration of 60 mM. Furthermore, the genes encoding GSTΩ significantly enhance the arsenite tolerance but not the arsenate tolerance of E. coli AW3110 (DE3) (ΔarsRBC). It can be deduced from these results that GSTΩs play an important role in arsenic detoxification in R. philippinarum.

人们越来越认识到活生物体中砷的主要危害。海洋软体动物易于积累高水平的砷，但是与海洋软体动物中的砷解毒有关的知识仍然不足。在这项研究中，研究了菲律宾蛤仔中砷的生物富集以及谷胱甘肽S-转移酶ω（GSTΩ）在解毒过程中的作用。水性暴露于As（III）或As（V）30天后的蛤。结果表明，the的累积砷水平明显高于消化腺。砷的甜菜碱（AsB）和砷酸二甲酯（DMA）占了大部分砷，而砷酸单甲酯（MMA）可以快速代谢。亚细胞分布分析表明，大多数砷存在于生物解毒的金属级分（包括富含金属的颗粒和类金属硫蛋白）中，表明它们在保护细胞免受砷毒性作用中具有重要作用。砷暴露后，两个编码GSTΩ的基因的相对mRNA表达上调，并且转录响应对As（III）的敏感性高于As（V）。重组GSTΩs在最佳条件下表现出高活性，尤其是在37°C和pH值为4-5的情况下，As（V）浓度为60 mM。此外，编码GSTΩ的基因显着增强了砷的耐受性，但没有增强砷的耐受性。大肠杆菌AW3110（DE3）（ΔarsRBC）。从这些结果可以推断出，GSTΩs在菲律宾蛤仔的砷解毒中起着重要作用。