Biomimetic catalysts designed on macromolecular scaffolds

Enzyme, an efficient and sophisticated biocatalyst, evolves into unique biomacromolecule with three-dimensional structure consisting of a linear sequence of amino acids and plays a crucial role in catalyzing biologically chemical reactions with high efficiency and selectivity in living system. For understanding the relationships between the enzyme structures and functions, the enzymatically catalytic mechanism, as well as for the potential applications, various biomimetic catalysts have been constructed to simulate the catalytic behavior of native enzymes. According to the wide studies in this area, the substrate recognition, specifically supramolecular interactions, and the cooperativity between the catalytic sites and substrate-binding sites have been regarded as pivotal factors for designing an efficient artificial enzyme. Up to now, large numbers of artificial enzymes have been constructed on various different scaffolds ranging from small molecular compounds, polymers, biomacromolecules to supramolecular assemblies and nanomaterials. Although most of the artificial enzymes showed moderate catalytic activities, encouragingly, some of them exhibited exciting high efficiency and selectivity. Compared to other scaffolds, macromolecules with their own advantages can endow enzyme models with enriched catalytic sites as well as the easy-achieved cooperation of the catalysis and recognition. This review will give an overview of the construction of artificial enzymes using macromolecules as scaffolds in the past decades, wherein various macromolecules containing copolymers, dendrimers, hyperbranched polymers, polymer microgels, supramolecules, imprinted polymers and biomacromolecules have been developed as scaffolds of artificial enzymes.