Developing photoactivated artificial enzymes for sustainable fuel production

Enzymes catalyze molecular reactions with remarkable efficiency and selectivity under mild conditions. Photoactivated enzymes make use of a light-absorbing chromophore to drive chemical transformations, ideally using sunlight as an energy source. The direct attachment of a chromophore to native enzymes is advantageous, as information on the underlying catalytic mechanisms can be obtained. Artificial enzyme development seeks to mimic natural enzymes to generate valuable products with high efficiency in a simplified, robust framework. Light-initiated artificial enzymatic catalysis combines these strategies and represents a promising avenue for sustainable generation of value-added products. Furthermore, while early systems often combined three components for catalysis-- the enzyme, a photosensitizer, and a sacrificial electron donor-- we describe an adaptation of this approach in which the chromophore is immobilized on the enzyme, removing the need for diffusional collision. The latter is advantageous as it provides deeper insight into the catalytic mechanism and facilitates further optimization of the designed construct. In this opinion, we highlight several examples of light-driven, artificial metalloenzymes, and suggest that ongoing and future efforts should leverage prior mechanistic studies on native enzymes as a foundation for strategic design of next-generation photoactivated protein-based catalysts.