Dynamic bond-driven encapsulation of enzymes in metal-organic frameworks beyond pore size constraints

Immobilizing enzymes in a metal-organic framework (MOF) is an effective approach to improve their stability and reusability, but the small pore sizes of most MOFs exclude many industrially relevant enzymes. Here, we present a dynamic bond-mediated approach that enables enzyme encapsulation beyond pore size constraints. We constructed a series of mesoporous MOFs by integrating robust trivalent metal-carboxylate clusters with dynamic divalent metal-pyridyl units. Systematic variation of metal combinations and linker lengths precisely tunes the framework stability and dynamics, enabling reversible dissociation and reformation of metal-pyridyl bonds. These dynamic bonds function as molecular gates, permitting enzymes larger than the intrinsic pores to infiltrate while preserving framework integrity. The strategy was applied to encapsulate diverse enzymes, preserving high enzymatic activity and enhancing operational stability. Furthermore, it supports the co-immobilization of multi-enzyme systems, such as NahK and GlmU, for efficient cascade synthesis of high-value glycosylated donors.