Ecofriendly approaches to efficiently enhance catalase performance

The present work reports on two approaches to enhance catalase (CAT) activity and its stability by using two simple, green processes. In the first procedure, CAT was transiently exposed to an ionic liquid (IL) in the presence of redox molecules related to CAT structure which resulted in partial denaturation. The other method, which uses high hydraulic pressure (HHP) to partially denature CAT (in the presence of redox molecules), has the advantage of being completely reagentless. In both cases, partial denaturation was followed by dialysis, hence refolding and entrapment of redox molecules within the modified 3-D CAT structure (affording a "wired" enzyme). The two approaches to enzyme "wiring" are discussed comparatively from the point of view of the parameters used during the procedure, residual enzyme activity, nature of the modifier, interaction between CAT and the redox molecules, antioxidant activity, and stability over time of the modified protein. Samples of CAT modified in the presence of iron sulfate heptahydrate from each series, respectively, were used to make enzyme electrodes which were tested as amperometric biosensors for hydrogen peroxide detection. Both showed catalytic effect and linear behavior and have potential for applications in the food industry, pharmaceuticals and the textile industry.