Design of selective esterification of triglyceride synthetic lipase based on specific fatty acids

The application of lipase as an environmentally friendly biocatalyst shows great potential in the synthesis of diverse lipids, particularly glycerol ester ω-3 polyunsaturated fatty acids (PUFA). However, most lipases demonstrate restricted activity and specificity towards long-chain unsaturated fatty acids, thereby hindering their ability to selectively produce glycerol ester ω-3 PUFA. This study outlines a strategy to design lipase MAS1 mutants aimed at enhancing substrate specificity towards docosahexaenoic acid (DHA) by increasing hydrogen bonding and reducing binding energy. Results indicated relatively high hydrolytic activity in mutant F62W (4950 U·mg⁻¹) compared to wild lipase (3810 U·mg⁻¹). Furthermore, the catalytic efficiency of F62W in the esterification of DHA to Triglycerides (TAG) was increased by 1.6-fold. The improved efficiency stems from a reduced distance for DHA catalytic attack, along with increased hydrogen bonds and salt bridges in the binding pocket. A significant decrease in the binding energy barrier for the esterification reaction was observed, reducing from −11.12 kcal/mol to −22.61 kcal/mol.