Rational design of CYP120A1 variants and eco-friendly alternatives for enhanced bioremediation of sulfonamide antibiotics

Bioremediation mediated by cytochrome P450 enzymes represents an effective strategy for the removal of Sulfonamides (SAs). However, the inherent limitations in the thermostability and catalytic activity of wild-type enzymes result in suboptimal remediation efficiency. Therefore, the development of highly efficient degradative enzymes is crucial for mitigating SAs pollution. Additionally, identifying environmentally friendly alternatives with lower toxicity is beneficial for source control of SAs. This work adopts an integrated strategy that combines bioremediation and source control. Utilizing multiple computational strategies, we rationally designed and screened novel high-efficiency enzyme variants of CYP120A1 specifically targeting SAs degradation, and concurrently evaluated the molecular properties of pollutants to design new green alternatives. This study successfully identified 18 single-mutation enzyme candidates with enhanced thermostability and catalytic activity. Furthermore, we designed three green alternatives, SDZ-13, SDZ-19, and SDZ-27, which exhibit lower toxicity and significantly improved binding affinity with the degradative enzymes. However, accurate and rapid identification of mutation sites and practical application of eco-friendly molecular design remain significant challenges for future research. This work provides theoretical support for the development of efficient degradative enzymes and the design of sustainable alternative compounds, contributing to the advancement of emerging pollutants pollution control strategies.