Discovery, expression, and characterization of highly tolerant superoxide dismutases from extremophiles for potential...

Superoxide dismutases (SODs) are essential enzymes that protect cells by converting harmful superoxide radicals into oxygen and hydrogen peroxide. However, their application in industrial and medical settings is often limited by poor stability under extreme conditions such as high temperatures, extreme pH, and oxidative stress. In this study, we identified and characterized two highly stable manganese-dependent SODs from extremophiles. These enzymes remained highly active at temperatures up to 80 °C, across a broad pH range (3.0-12), and in the presence of oxidative agents and denaturing chemicals. Structural analysis revealed that their exceptional stability is attributed to tightly folded structures, strong hydrophobic cores, and robust metal-binding sites. Both OsSOD and GtSOD demonstrated robust catalytic performance, with k_catk_m values of 2.29 × 10⁷ and 1.06 × 10⁷ M^-1·s^-1, respectively. In cell-based models, they effectively reduced oxidative stress and inflammation, indicating potential for antioxidant therapy. Additionally, their long-term stability supports their use in cosmetic and pharmaceutical formulations. Overall, these extremophile-derived SODs are highly stable and efficient enzymes with broad potential for industrial, medical, and cosmetic applications.