Channel-Directed Enzymatic Depolymerization within a Metal-Organic Framework.

Controlled growth of metal-organic frameworks (MOFs) under mild conditions has enabled the production of hybrid biocomposites with potential applications in biocatalysis. While the structure and bioactivity of confined enzymes are retained, improving the mass transport across the porous architecture remains a challenge. Here, we report a biocompatible and scalable synthetic procedure of a phase-pure aluminum trimesate porous framework, MIL-110(Al), featuring accessible microporous channels. The method is compatible with the encapsulation of enzymes via a Lewis acid-mediated mineralization, reaching high efficiencies, and with control over protein loading. Moreover, we demonstrate a favored channel-directed depolymerization in a model biocomposite, xylanase@MIL-110(Al), which successfully hydrolyzes the xylan polymer over consecutive cycles. This work emphasizes the possibility of improving the overall enzymatic performance in depolymerization reactions by using MOF-protective scaffolds featuring large accessible porosity.