Concentrations of nucleophilic sulfur species in small Indian mongoose (Herpestes auropunctatus) in Okinawa, Japan
Concentrations of nucleophilic sulfur species in small Indian mongoose (Herpestes auropunctatus) in Okinawa, Japan
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DOI：
10.1016/j.chemosphere.2022.133833
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发表时间：
2022-02-07
期刊：
影响因子：
8.8
通讯作者：
Kumagai，Yoshito
中科院分区：
文献类型：
--
作者：
Horai，Sawako;Abiko，Yumi;Kumagai，Yoshito
反应性硫物质（RSS），例如氢全（多）硫化物、半胱氨酸全（多）硫化物、谷胱甘肽全（多）硫化物和蛋白质结合的全（多）硫化物，由于它们的高亲核性，可以容易地与环境亲电试剂例如甲基汞（MeHg）反应。这些RSS由诸如胱硫醚β-合酶（CBS）和胱硫醚γ-裂解酶（CSE）的酶产生，并且在哺乳动物器官中发现。野生动物的器官还没有被分析过硫化氢，半胱氨酸，谷胱甘肽和RSS。本研究以β-（4-羟基苯基）乙基碘乙酰胺为捕获剂，采用稳定同位素稀释法对小印度獴体内的低分子量亲核硫物质（包括RSS）进行定量分析。Western印迹法显示猫鼬器官（肝脏、肾脏、大脑和小脑）含有与抗CBS和CSE抗体交叉反应的蛋白质。这些酶的表达模式与小鼠相似，表明猫鼬器官含有CBS和CSE。此外，在该物种的肝脏中发现了与甲基汞相比毒性较低的硫化二甲基汞（MeHg）2S。这些结果表明，小印度猫鼬产生RSS和monothiols与解毒的亲电有机汞。体内汞含量高的动物可能具有汞解毒功能，这不仅与硒有关，还与RSS有关。
Reactive sulfur species (RSS), such as hydrogen per (poly)sulfide, cysteine per (poly)sulfide, glutathione per (poly)sulfide, and protein-bound per (poly)sulfides, can easily react with environmental electrophiles such as methylmercury (MeHg), because of their high nucleophilicity. These RSS are produced by enzymes such as cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) and are found in mammalian organs. Organs of wildlife have not been analyzed for hydrogen sulfide, cysteine, glutathione, and RSS. In this study, low molecular weight nucleophilic sulfur substances, including RSS, were quantified by stable isotope dilution assay-based liquid chromatography-mass spectrometry using β-(4-hydroxyphenyl)ethyl iodoacetamide to capture the target chemicals in the small Indian mongoose which species possesses high mercury content as same as some marine mammals. Western blotting revealed that the mongoose organs (liver, kidney, cerebrum, and cerebellum) contained proteins that cross-reacted with anti-CBS and CSE antibodies. The expression patterns of these enzymes were similar to those in mice, indicating that mongoose organs contain CBS and CSE. Moreover, bis-methylmercury sulfide (MeHg)2S, which is a low toxic compound in comparison to MeHg, was found in the liver of this species. These results suggest that the small Indian mongoose produces RSS and monothiols associated with detoxification of electrophilic organomercury. The animals which have high mercury content in their bodies may have function of mercury detoxification involved not only Se but also RSS interactions.