It is known that textile dyes have various risks on human health. Glutathione-S-transferase enzymes play a critical role in the detoxification of xenobiotics in living systems. This study aimed to examine the interaction of methylene blue with human erythrocyte glutathione-S-transferase purified in one step. Human erythrocyte glutathione-S-transferase was purified with approximately 750-fold purification and 30% efficiency by glutathione agarose affinity chromatography. The results showed that the enzyme was inhibited by methylene blue with an IC₅₀ value of 1.40 mmol/L. The Ki constant of methylene blue was 1.17 mmol/L. The Lineweaver–Burk graph of the methylene blue showed that the type of inhibition was compatible with mixed type inhibition. A new third spot was also detected by thin-layer chromatography. Furthermore, the cytotoxicity of methylene blue on human erythrocytes was evaluated and it was found that the haemolysis per cent of methylene blue on erythrocytes was approximately 14%.

中文翻译：

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从人红细胞中纯化的亚甲蓝和谷胱甘肽-S-转移酶的相互作用

众所周知，纺织染料对人体健康具有多种风险。谷胱甘肽-S-转移酶在生物系统中异种生物的解毒中起关键作用。这项研究旨在检查亚甲基蓝与一步纯化的人类红细胞谷胱甘肽-S-转移酶的相互作用。通过谷胱甘肽琼脂糖亲和层析，以约750倍的纯化和30％的效率纯化人红细胞谷胱甘肽-S-转移酶。结果表明，该酶被亚甲基蓝抑制，IC ₅₀值为1.40 mmol / L。亚甲基蓝的Ki常数为1.17 mmol / L。亚甲基蓝的Lineweaver–Burk图显示抑制类型与混合类型抑制兼容。通过薄层色谱法也检测到新的第三点。此外，评估了亚甲基蓝对人红细胞的细胞毒性，发现亚甲基蓝在红细胞上的溶血百分比约为14％。