Stabilization of an enzyme cytochrome c in a metal-organic framework against denaturing organic solvents

Summary Enzymes are promising catalysts with high selectivity and activity under mild reaction conditions. However, their practical application has largely been hindered by their high cost and poor stability. Metal-organic frameworks (MOFs) as host materials show potential in protecting proteins against denaturing conditions, but a systematic study investigating the stabilizing mechanism is still lacking. In this study, we stabilized enzyme cytochrome c (cyt c) by encapsulating it in a hierarchical mesoporous zirconium-based MOF, NU-1000 against denaturing organic solvents. Cyt c@NU-1000 showed a significantly enhanced activity compared to the native enzyme, and the composite retained this enhanced activity after treatment with five denaturing organic solvents. Moreover, the composite was recyclable without activity loss for at least three cycles. Our cyt c@NU-1000 model system demonstrates that enzyme@MOF composites prepared via post-synthetic encapsulation offer a promising route to overcome the challenges of enzyme stability and recyclability that impede the widespread adoption of biocatalysis.
Graphical abstract
Highlights • Catalytic activity of cytochrome c was protected against denaturing organic solvents • The mesoporous MOF stabilized cytochrome c by preventing enzyme aggregation • The enzyme@MOF composite was recyclable for at least three cycles • This enzyme@MOF system is promising for developing robust biocatalyst
Chemistry; Green chemistry; Engineering; Biocatalysis; Materials chemistry