Activity Modulation of an Enzyme in a Confined Space.

Enzyme immobilization in metal-organic frameworks (MOFs) features improved catalytic efficiency, enhanced stability, and good recyclability. However, remote modulation of enzymatic activity in a confined space has never been reported, despite its great significance in biochemical systems. Here we develop a photoresponsive system with remote controllability in terms of the activity of an enzyme in a confined space. The photoresponsive inhibitor (PRI) is decorated on the pore walls of a mesoporous MOF, PCN-128, followed by the introduction of an enzyme (carbonic anhydrase (CA)). Upon visible-light irradiation, PRI is in its trans state and docks at the active site of CA, inhibiting the enzymatic activity. Upon exposure to UV-light radiation, PRI undergoes isomerization to its cis configuration and subsequently dissociates from the enzyme's active site, leading to a 66.7% enhancement in its catalytic activity. In contrast, free inhibitors demonstrate poor regulating performance. This strategy enables reversible regulation of the enzyme's natural function in a confined space through light-controlled noncovalent interactions.