Microenvironment Engineering in Functionalized MIL-101(Cr) for Enhanced Biocatalytic Performance: Mechanisms and Applications in Inositol Synthesis

Enzyme immobilization is a key strategy to improve the industrial viability of biocatalysts. While metal–organic frameworks (MOFs) have shown great promise as immobilization carriers, challenges remain in achieving enzyme-specific design and gaining a molecular-level understanding of the interface interactions. In this study, we employed MIL-101(Cr) and its derivatives functionalized with −CH 3, −NO 2, and −SO 3 H groups to host inositol-1-phosphate synthase (IPS), aiming to precisely tailor the microenvironments and enzyme–carrier interactions. The immobilized composites, particularly those with methyl modification, demonstrated superior catalytic efficiency and operational stability over those of the free enzyme. Experimental and theoretical analyses revealed that the enhanced performance originates from the high specific surface area and a hydrophobic microenvironment, which mitigate conformational deformation, improve substrate accessibility, and optimize the binding and release pathways for substrates and products. This work provides a rational design strategy for enzyme-oriented immobilization and underscores the potential of functionalized MIL-101 in advanced biocatalysis.