Comparison of Fungal Thermophilic and Mesophilic Catalase-Peroxidases for Their Antioxidative Properties

Comparison of Fungal Thermophilic and Mesophilic Catalase-Peroxidases for Their Antioxidative Properties

WoS Article

Catalase-peroxidases (KatGs) are unique bifunctional oxidoreductases that contain heme in their active centers allowing both the peroxidatic and catalatic reaction modes. These originally bacterial enzymes are broadly distributed among various fungi allowing them to cope with reactive oxygen species present in the environment or inside the cells. We used various biophysical, biochemical, and bioinformatics methods to investigate differences between catalase-peroxidases originating in thermophilic and mesophilic fungi from different habitats. Our results indicate that the architecture of the active center with a specific post-translational modification is highly similar in mesophilic and thermophilic KatG and also the peroxidatic acitivity with ABTS, guaiacol, and L-DOPA. However, only the thermophilic variant CthedisKatG reveals increased manganese peroxidase activity at elevated temperatures. The catalatic activity releasing molecular oxygen is comparable between CthedisKatG and mesophilic MagKatG1 over a broad temperature range. Two constructed point mutations in the active center were performed selectively blocking the formation of described post-translational modification in the active center. They exhibited a total loss of catalatic activity and changes in the peroxidatic activity. Our results indicate the capacity of bifunctional heme enzymes in the variable reactivity for potential biotech applications.

Catalase-peroxidases (KatGs) are unique bifunctional oxidoreductases that contain heme in their active centers allowing both the peroxidatic and catalatic reaction modes. These originally bacterial enzymes are broadly distributed among various fungi allowing them to cope with reactive oxygen species present in the environment or inside the cells. We used various biophysical, biochemical, and bioinformatics methods to investigate differences between catalase-peroxidases originating in thermophilic and mesophilic fungi from different habitats. Our results indicate that the architecture of the active center with a specific post-translational modification is highly similar in mesophilic and thermophilic KatG and also the peroxidatic acitivity with ABTS, guaiacol, and L-DOPA. However, only the thermophilic variant CthedisKatG reveals increased manganese peroxidase activity at elevated temperatures. The catalatic activity releasing molecular oxygen is comparable between CthedisKatG and mesophilic MagKatG1 over a broad temperature range. Two constructed point mutations in the active center were performed selectively blocking the formation of described post-translational modification in the active center. They exhibited a total loss of catalatic activity and changes in the peroxidatic activity. Our results indicate the capacity of bifunctional heme enzymes in the variable reactivity for potential biotech applications.

peroxidase-catalase superfamily; heme catalase; bifunctional enzyme; reactive oxygen species; oxidative stress

peroxidase-catalase superfamily; heme catalase; bifunctional enzyme; reactive oxygen species; oxidative stress

POLJOVKA, A.; MUSIL, M.; BEDNÁŘ, D.; CHOVANOVÁ, K.; BAUEROVÁ-HLINKOVÁ, V.; BELLOVÁ, J.; KOHÚTOVÁ, L.; BARÁTH, P.; ZÁMOCKÝ, M.

2024

04.07.2023

MDPI

BASEL

2076-3921

Antioxidants

12

7

Swiss Confederation

1

19

19

https://www.mdpi.com/2076-3921/12/7/1382

http://hdl.handle.net/11012/244988

antioxidants-12-01382