Receptor-Based Artificial Metalloenzymes on Living Human Cells
Artificial metalloenzymes are known to be promising tools for biocatalysis, but their recent compartmentalization has led to compatibly with cell components thus shedding light on possible therapeutic applications. We prepared and characterized artificial metalloenzymes based on the A2A adenosine receptor embedded in the cytoplasmic membranes of living human cells. The wild type receptor was chemically engineered into metalloenzymes by its association with strong antagonists that were covalently bound to copper(II) catalysts. The resulting cells enantioselectively catalyzed the abiotic Diels–Alder cycloaddition reaction of cyclopentadiene and azachalcone. The prospects of this strategy lie in the organ-confined in vivo preparation of receptor-based artificial metalloenzymes for the catalysis of reactions exogenous to the human metabolism. These could be used for the targeted synthesis of either drugs or deficient metabolites and for the activation of prodrugs, leading to therapeutic tools with unforeseen applications.
Synthesis of a Heterogeneous Artificial Metallolipase with Chimeric Catalytic Activity
A solid-phase strategy using lipase as a biomolecular scaffold to produce a large amount of Cu2+-metalloenzyme is proposed here. The application of this protocol on different 3D cavities of the enzyme allows creating a heterogeneous artificial metallolipase showing chimeric catalytic activity. The artificial catalyst was assessed in Diels–Alder cycloaddition reactions and cascade reactions showing excellent catalytic properties.
Host protein: Lipase from G. thermocatenulatus (GTL)Anchoring strategy: CovalentOptimization: GeneticReaction: Diels-Alder cycloadditionMax TON: 411ee: 92PDB: ---Notes: ArM is immobilized on Sepabeads. Endo/exo = 93.5%
Host protein: Lipase from G. thermocatenulatus (GTL)Anchoring strategy: CovalentOptimization: GeneticReaction: ReductionMax TON: ---ee: ---PDB: ---Notes: Cascade reaction: Ester hydrolysis (natural function of the host protein) followed by reduction (function of the designed ArM).