Improvement of catalytic activity of sorbose dehydrogenase for deoxynivalenol degradation by rational design

Deoxynivalenol (DON) is the most frequently contaminated mycotoxin in food and feed worldwide, causing significant economic losses and health risks. Physical and chemical detoxification methods are widely used, but they cannot efficiently and specifically remove DON. In the study, the combination of bioinformatics screening and experimental verification confirmed that sorbose dehydrogenase (SDH) can effectively convert DON to 3keto-DON and a substance that removes four hydrogen atoms for DON. Through rational design, the Vmax of the mutants F103L and F103A were increased by 5 and 23 times, respectively. Furthermore, we identified catalytic sites W218 and D281. SDH and its mutants have broad application conditions, including temperature ranges of 10-45 degrees C and pH levels of 4-9. Additionally, the half-lives of F103A at 90 degrees C (processing temperature) and 30 degrees C (storage temperature) were 60.1 min and 100.5 d, respectively. These results suggest that F103A has significant potential in the detoxification application of DON.

Automated summary

This study identified sorbose dehydrogenase (SDH) as an effective enzyme for converting deoxynivalenol (DON) to 3keto-DON and a substance that removes four hydrogen atoms. Mutants F103L and F103A showed significantly increased reaction rates. The study also identified catalytic sites W218 and D281. SDH and its mutants have broad application conditions, and F103A showed potential for detoxification of DON.