Glutathione peroxidases (GPx) are a family of enzymes with the ability to reduce organic and inorganic hydroperoxides to the corresponding alcohols using glutathione or thioredoxin as an electron donor. Here, we report the functional and structural characterization of a GPx identified in Trichoderma reesei (TrGPx). TrGPx was recombinantly expressed in a bacterial host and purified using affinity. Using a thioredoxin coupled assay, TrGPx exhibited activity of 28 U and 12.5 U in the presence of the substrates H₂O₂ and t-BOOH, respectively, and no activity was observed when glutathione was used. These results indicated that TrGPx is a thioredoxin peroxidase and hydrolyses H₂O₂ better than t-BOOH. TrGPx kinetic parameters using a pyrogallol assay resulted at K_mapp = 11.7 mM_, V_maxapp = 10.9 IU/μg TrGPx, k_cat = 19 s⁻¹ and a catalytic efficiency of 1.6 mM⁻¹ s⁻¹ to H₂O₂ as substrate. Besides that, TrGPx demonstrated an optimum pH ranging from 9.0–12.0 and a half-life of 36 min at 80 °C. TrGPx 3D-structure was obtained in a reduced state and non-catalytic conformation. The overall fold is similar to the other phospholipid-hydroperoxide glutathione peroxidases. These data contribute to understand the antioxidant mechanism in fungi and provide information for using antioxidant enzymes in biotechnological applications.

谷胱甘肽过氧化物酶（GPx）是一类酶，能够使用谷胱甘肽或硫氧还蛋白作为电子供体，将有机和无机氢过氧化物还原为相应的醇。在这里，我们报告在里氏木霉（TrGPx）中鉴定的GPx的功能和结构表征。TrGPx在细菌宿主中重组表达并使用亲和力纯化。使用硫氧还蛋白偶联测定，在底物H ₂ O ₂和t -BOOH存在下，TrGPx分别显示28 U和12.5 U的活性，使用谷胱甘肽时未观察到活性。这些结果表明TrGPx是硫氧还蛋白过氧化物酶并且水解H ₂ O _2。比t -BOOH好。使用邻苯三酚测定法得出的TrGPx动力学参数为K _mapp  = 11.7 mM _， V _maxapp  = 10.9 IU /μgTrGPx，k _cat  = 19 s ^-1和1.6 mM ^-1  s ^-1对H ₂ O ₂的催化效率作为基材。除此之外，TrGPx的最佳pH值在9.0-12.0之间，在80°C下的半衰期为36分钟。TrGPx 3D结构以还原状态和非催化构象获得。总体折叠类似于其他磷脂-氢过氧化物谷胱甘肽过氧化物酶。这些数据有助于了解真菌中的抗氧化机理，并提供在生物技术应用中使用抗氧化酶的信息。