Abstract：
Exposure to arsenic can cause various biological effects by increasing the production of reactive oxygen species (ROS). Selenium acts as a beneficial element by regulating ROS and limiting heavy metal uptake and translocation. There are studies on the interactive effects of As and Se in plants, but the antagonistic and synergistic effects of these elements based on their binding to glutathione (GSH) molecules have not been studied yet. In this study, we aimed to investigate the antagonistic or synergistic effects of As and Se on the binding mechanism of Se and As with GSH at pH 3.0, 5.0, or 6.5. The interaction of As and Se in Se(SG)2 + As(III) or As(SG)3 + Se(IV) binary systems and As(III) + Se(IV) + GSH ternary system were examined depending on their ratios via liquid chromatography diode array detector/electrospray mass spectrometry (LC-DAD/MS) and liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). The results showed that the formation of As(GS)3 was not detected in the As(III) + Se(SG)2 binary system, indicating that As(III) did not affect the stability of Se(SG)2 complex antagonistically. However, in the Se(IV) + As(SG)3 binary system, the addition of Se(IV) to As(SG)3 affected the stability of As(SG)3 antagonistically. Se(IV) reacted with GSH, disrupting the As(SG)3 complex, and consequently, Se(SG)2 formation was measured using LC-MS/DAD. In the Se(IV) + GSH + As(III) ternary system, Se(SG)2 formation was detected upon mixing As(III), Se(IV), and GSH. The increase in the concentration of As(III) did not influence the stability of the Se(SG)2 complex. Additionally, Se(IV) has a higher affinity than As(III) to the GSH, regardless of the pH of the solution. In both binary and ternary systems, the formation of the by-product glutathione trisulfide (GSSSG) was detected using LC-ESI-MS/MS.
摘要：
暴露于砷可以通过增加活性氧（ROS）的产生而引起各种生物学效应。硒通过调节ROS并限制重金属的吸收和转运而作为有益元素。有关于As和Se在植物中的相互作用的研究，但是尚未研究这些元素基于与谷胱甘肽（GSH）分子结合的拮抗和协同作用。在这项研究中,我们旨在研究As和Se在pH3.0、5.0或6.5时对Se和As与GSH的结合机制的拮抗或协同作用。通过液相色谱二极管阵列检测器/电喷雾质谱（LC-DAD/MS）和液相色谱-电喷雾串联质谱（ESI-MS/MS）检查了Se（SG）2As（III）或As（SG）3Se（IV）二元系统和As（III）Se（IV）GSH三元系统中As和Se的相互作用。结果表明，在As(III)+Se(SG)2二元系统中未检测到As(GS)3的形成，表明As（III）对Se（SG）2复合物的稳定性没有拮抗作用。然而,在Se(IV)+As(SG)3二元系统中，在As(SG)3中添加Se(IV)对As(SG)3的稳定性有拮抗作用。Se(IV)与GSH反应，破坏As（SG）3复合物，因此，使用LC-MS/DAD测量Se(SG)2形成。在Se(IV)+GSH+As(III)三元体系中，在混合As(III)时检测到Se(SG)2的形成，Se(IV),GSH。As（III）浓度的增加不会影响Se（SG）2复合物的稳定性。此外,Se（IV）比As（III）对GSH具有更高的亲和力，无论溶液的pH值如何。在二元和三元系统中，使用LC-ESI-MS/MS检测副产物谷胱甘肽三硫化物(GSSSG)的形成。
