Amino Acid Ionic Liquid-Functionalized Magnetic Interface-Induced Directional Enrichment and Immobilization of Active Conformations of Lipase

The development of high-performance immobilized enzymes is critical for advancing industrial biocatalysis in the food and agricultural fields. In this work, Candida rugosa lipase (CRL) was precisely immobilized on magnetic chitosan carriers functionalized with amino acid ionic liquids (AAIL), forming a stable biocatalytic platform. The immobilized lipase showed significantly improved thermal stability, organic solvent resistance, and storage stability. Molecular dynamics simulations revealed that the carrier enhanced enzyme rigidity, while AAIL regulated enzyme lid movement, optimized catalytic site distances, and stabilized the catalytic triad, increasing the active conformation ratio from 37% to 68%. Applied in phytosterol ester synthesis, it achieved a 94.4% esterification yield and retained nearly 70% efficiency after six cycles. This work provides guidance for high-efficiency biocatalysts and green biocatalysis development.