Overexpression and truncation of a novel cold-adapted lipase with improved enzymatic characteristics

The novel cold-adapted lipase (Lip ZC12) derived from Psychrobacter sp. ZY124 exhibited higher catalytic activity at 20-40 °C, the whole gene was then sequenced, analyzed, and overexpressed. However, its intrinsic structural characteristics lead to a decreased affinity toward the substrate, thus limiting the improvement of catalytic efficiency. Modeling the homologous structure and simulating the binding process of Lip ZC12 with the substrate. It was found that truncated lid (lip-Δlid) could not only increase the k_cat, but also significantly enhance the substrate affinity, the substrate affinity and catalytic efficiency of Lip ZC12 modified by lid truncation were significantly improved. The results revealed that the k_cat/K_m value of lip-Δlid was 1.6 times higher than that of free lipase. This improved catalytic performance of cold-adapted lipase, and these findings laid an important foundation for further application.