Enhanced Ultraviolet Light Tolerance of Peroxidase Intercalated into Titanate Layers

Ultraviolet (UV)-light-induced deactivation (photodenatruation) of enzymes (horseradish peroxidase, HRP) with a limited photostability is drastically inhibited by intercalation into two-dimensional (2D) nanospaces surrounded with semiconducting titanate layers. The enzyme existing in the interlayer can react with substrate molecule through a semiopen structure along the 2D layers even after the incorporation. The UV light is absorbed by the layers with band gaps equivalent to UV regions and then the photodenaturation of bound HRP is retarded in comparison with the native one. It is demonstrated that the optical absorption property of the titanate host layer and the pH-dependent affinity with the guest strongly influence the UV light tolerance of HRP in the interlayer space.