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The mechanism for the GPx reactions is shown in Figure 3.
GPx 反應的機構如圖 3 所示。

The first step is an oxidation of the selenol group of the enzyme by a hydroperoxide to form a selenic acid derivative (ESeOH).
第一步是利用一個過氧化物，把酶中的硒醇基團氧化成硒酸的衍生物（EseOH）。

The second step leads to the formation of covalent bonding between the sulfur of the GSH and the selenium of the enzyme to form a selenenyl sulfide adduct (ESeSG).
第二步導致在酶中的硒與GSH的硫之間形成共價鍵，生成硒化物與硫化物的加合物（ESeSG）。

The last step is the regeneration of the reduced enzyme via a second GSH that breaks the selenadisulfide bridge in ESeSG [34] (see Figure 3).
最後一步是通過第二個 GSH 斷裂 ESeSG [34]（參看圖3）中的硒二硫跨接，從而再生出被還原的酶。

GPx: glutathjione peroxidase,麩胱甘肽過氧化酵素
GSH: glutationone, 麩胱甘肽
hydroperoxide 氫過氧化物