Catalases, heme or manganese, are efficient biocatalysts that split hydrogen peroxide into water and oxygen. We have cloned a manganese catalase from thermophilic bacterium, Geobacillus thermopakistaniensis, and expressed the corresponding gene in Escherichia coli. The gene product, Cat_Gt, was synthesized in E. coli as inactive inclusion bodies. Solubilization and refolding of the inclusion bodies resulted in highly active Cat_Gt with a specific activity of 18,521 μmol min⁻¹ mg⁻¹. The refolded protein exhibited apparent K_m and k_cat values of 260 mM and 10,360 s⁻¹ subunit⁻¹, respectively. It exhibited a half-life of 1 h at 100 °C. The unique features of Cat_Gt are its high activity and thermostability. These features make it a valuable catalyst for industrial applications. To the best of our knowledge, Cat_Gt is the most thermostable catalases characterized to date.

中文翻译：

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来自热土芽孢杆菌的高度稳定的锰过氧化氢酶：分子克隆和表征。

触媒，血红素或锰是有效的生物催化剂，可将过氧化氢分解成水和氧气。我们已经从嗜热细菌热巴氏芽孢杆菌中克隆了一种锰过氧化氢酶，并在大肠杆菌中表达了相应的基因。基因产物Cat _Gt在大肠杆菌中合成为非活性包涵体。包涵体的溶解和重折叠导致高活性的Cat _Gt，比活性为18,521μmolmin ^-1  mg ^-1。重新折叠的蛋白质表现出260 mM和10,360 s ^-1的表观K _m和k _cat值亚单元^-1。在100°C下的半衰期为1 h。Cat _Gt的独特功能是其高活性和热稳定性。这些特性使其成为工业应用的重要催化剂。据我们所知，Cat _Gt是迄今为止最热稳定的过氧化氢。