Exploiting the activity-stability trade-off of glucose oxidase from Aspergillus niger using a simple approach to calculate thermostability of mutants

Glucose oxidase (Gox) is a biocatalyst that is widely applied in the food industry, as well as other biotechnological industries. However, the industrial application of Gox is hampered by its low thermostability and activity. Here, we aimed to improve the thermostability of GoxM4 from Aspergillus niger without reducing its activity due to the activity-stability trade-off. A simple and effective approach combining enzyme activity and structure stability was adopted to evaluate the thermostability of GoxM4 and its mutants. After four rounds of computeraided rational design, the best mutant, GoxM8, was obtained. The melting temperature (Tm) of GoxM8 was increased by 9 degrees C compared with GoxM4. The catalytic efficiency of GoxM8 was similar to GoxM4, suggesting that the enzyme activity-stability trade-off was counteracted. To explore its mechanism, we performed molecular dynamics simulations of GoxM4 and its mutants. Our findings provided a typical example for researching the enzyme activity-stability trade-off.

Automated summary

The study successfully improved the thermostability of GoxM4 from Aspergillus niger by combining enzyme activity and structure stability, obtaining a more stable mutant, GoxM8. The mutant showed a significant increase in melting temperature (Tm) compared to GoxM4, while maintaining a similar catalytic efficiency, effectively addressing the activity-stability trade-off in enzymes. The research provided a typical example for investigating the balance between enzyme activity and stability.