Engineered lipase from Thermomyces dupontii with improved thermostability for preparation of long-medium-long structured lipids

Lipase from Thermomyces dupontii (TDL) shows great potential to prepare long-medium-long structured lipids (LML-SLs), but its poor thermostability represents a significant obstacle to further industrial application. Herein, a rational design based on structure and sequence analysis (including disulfide bond calculation and sequence alignment) was used to generate a more thermostable mutant. Compared with wild-type TDL, mutant M3 displayed a 9.1-fold, 7.2 °C and 10 °C increase in half-life (t1/2) at 60 °C, the half-loss temperature (T 50) at 15 min and optimum temperature, respectively. Remarkably, the specific activity of mutant M3 was 49.1% higher than that of wild-type TDL. Molecular dynamics (MD) simulations showed that the structural flexibility of mutant M3 was reduced, which might contribute to the enhanced thermostability. Additionally, LML-SLs were synthesized from ethyl linoleate and tricaprylin with wild-type TDL and mutant M3. Compared with the wild-type TDL group, the LML-SL content of the mutant M3 group increased by 8.1%. This study will pave the way for the industrial application of TDL and provide valuable insights for enhancing the thermostability of other lipases. •The mutation design of TDL lipase was based on structure and sequence analysis.•Mutant M3 showed greatly increased thermostability.•Molecular dynamics simulations showed the rigidity of the mutant M3 was enhanced.•Mutant M3 showed enhanced effect in producing Long-medium-long structured lipids.