Glutathione S-transferase (GST) detoxifies a broad spectrum of xenobiotics, especially in chemotherapeutic drugs, endogenous molecules, and environmental pollutants. Since the enzyme metabolizes toxic compounds, it has been extensively studied in many living things including aquatic organisms. In the current study, the GST enzyme was purified from brown meagre (Sciaena umbra) muscle tissue for the first time. Then, kinetic parameters of the enzyme were determined as optimum ionic strength: 20 mM Tris/HCl, optimum pH: 7.0 (Tris/HCl), and optimum substrate concentration: 3.125 mM. Eventually, inhibitory effects of the heavy metals were evaluated. IC₅₀ values of the tested metal ions were calculated to be 0.1112, 0.6113, 0.727, and 0.7774 mM for Cd²⁺, Fe³⁺, Ag⁺, and Cu²⁺, respectively. Our results show that these heavy metals inhibit GST at very low concentrations which could cause dangerous results for aquatic systems.

中文翻译：

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褐藻 (Sciaena umbra) 谷胱甘肽 S- 转移酶的表征及其对重金属的抑制作用

谷胱甘肽 S-转移酶 (GST) 可以解毒广谱的外源性物质，特别是在化疗药物、内源性分子和环境污染物中。由于该酶代谢有毒化合物，因此已在包括水生生物在内的许多生物中进行了广泛的研究。在目前的研究中，GST 酶首次从褐色稀薄 ( Sciaena umbra ) 肌肉组织中纯化出来。然后，酶的动力学参数确定为最佳离子强度：20 mM Tris/HCl，最佳 pH：7.0 (Tris/HCl)，最佳底物浓度：3.125 mM。最后，评估了重金属的抑制作用。^{对于Cd 2+}、Fe ，所测金属离子的IC ₅₀值计算为0.1112、0.6113、0.727和0.7774 mM³⁺、Ag ⁺和Cu ²⁺。我们的研究结果表明，这些重金属在非常低的浓度下会抑制 GST，这可能会对水生系统造成危险的结果。