Comparing Ligninolytic Capabilities of Bacterial and Fungal Dye-Decolorizing Peroxidases and Class-II Peroxidase-Catalases

International Journal of Molecular Sciences

Dolores Linde¹  AngelT. Martínez¹  Marcos Laloux¹  Iván Ayuso-Fernández¹  FranciscoJ. Ruiz-Dueñas¹  JoséE. Aguiar-Cervera¹  AntonioL. de Lacey² 

[1] Centro de Investigaciones Biológicas “Margarita Salas” (CIB), CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain;Instituto de Catálisis y Petroleoquímica (ICP), CSIC, Marie Curie 2, E-28049 Madrid, Spain;

关键词: lignin transformation;    dye-decolorizing peroxidases;    lignin peroxidases;    versatile peroxidases;    lignin model dimers;    reduction potential;   

DOI  :  10.3390/ijms22052629

来源: DOAJ

【 摘 要 】

We aim to clarify the ligninolytic capabilities of dye-decolorizing peroxidases (DyPs) from bacteria and fungi, compared to fungal lignin peroxidase (LiP) and versatile peroxidase (VP). With this purpose, DyPs from Amycolatopsis sp., Thermomonospora curvata, and Auricularia auricula-judae, VP from Pleurotus eryngii, and LiP from Phanerochaete chrysosporium were produced, and their kinetic constants and reduction potentials determined. Sharp differences were found in the oxidation of nonphenolic simple (veratryl alcohol, VA) and dimeric (veratrylglycerol-β- guaiacyl ether, VGE) lignin model compounds, with LiP showing the highest catalytic efficiencies (around 15 and 200 s⁻¹·mM⁻¹ for VGE and VA, respectively), while the efficiency of the A. auricula-judae DyP was 1–3 orders of magnitude lower, and no activity was detected with the bacterial DyPs. VP and LiP also showed the highest reduction potential (1.28–1.33 V) in the rate-limiting step of the catalytic cycle (i.e., compound-II reduction to resting enzyme), estimated by stopped-flow measurements at the equilibrium, while the T. curvata DyP showed the lowest value (1.23 V). We conclude that, when using realistic enzyme doses, only fungal LiP and VP, and in much lower extent fungal DyP, oxidize nonphenolic aromatics and, therefore, have the capability to act on the main moiety of the native lignin macromolecule.

【 授权许可】

Unknown