Download MendeleyA Single Amino Acid Substitution Reprograms ROS Selectivity and Catalytic Function in DyP Peroxidases.
Zitare, U.A., Castro, M.A., Scocozza, M.F., Borges, P.T., Martins, L.O., Murgida, D.H.(2026) Inorg Chem
- PubMed: 42295056 Search on PubMed
- DOI: https://doi.org/10.1021/acs.inorgchem.6c02237
- Primary Citation Related Structures:
9U2X - PubMed Abstract:
Dye-decolorizing peroxidases (DyPs) are heme enzymes with broad substrate scope and increasing biotechnological relevance, yet the structural determinants governing their activation by reactive oxygen species (ROS) remain incompletely understood. Here, we identify dynamic ROS gating as a mechanism controlling activation and catalytic efficiency through a comparative study of two class I DyPs from Bacillus subtilis ( Bs DyP) and Thermobifida fusca ( Tfu DyP), together with the Bs DyP N244L variant. By combining steady-state kinetics, ROS-selective electroreductive activation assays, UV-vis and resonance Raman spectroscopy, X-ray crystallography, and molecular dynamics simulations, we establish a direct structure-function relationship linking distal heme pocket organization and access-tunnel architecture to enzyme-specific ROS preferences. Bs DyP WT is preferentially activated via • OH, whereas Tfu DyP relies mainly on H 2 O 2 . Remarkably, the single N244L substitution shifts the catalytic, structural, and dynamical properties of Bs DyP toward those of Tfu DyP, making both enzymes nearly indistinguishable in ROS usage and catalytic efficiency. This convergence arises from a reorganization of distal hydrogen-bonding networks and loop-mediated reshaping of the access tunnels, which together bias ROS accessibility and lower the barrier for compound I formation. These findings establish ROS gating as the principal determinant of DyP activation and provide a mechanistic framework for tuning ROS selectivity through protein engineering.
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires C1428EGA, Argentina.
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