A Designed Functional Metalloenzyme that Reduces O2 to H2O with Over One Thousand Turnovers
Rational design of functional enzymes with a high number of turnovers is a challenge, especially those with a complex active site, such as respiratory oxidases. Introducing two His and one Tyr residues into myoglobin resulted in enzymes that reduce O2 to H2O with more than 1000 turnovers (red line, see scheme) and minimal release of reactive oxygen species. The positioning of the Tyr residue is critical for activity.
Alteration of the Oxygen-Dependent Reactivity of De Novo Due Ferri Proteins
De novo proteins provide a unique opportunity to investigate the structure–function relationships of metalloproteins in a minimal, well-defined and controlled scaffold. Here, we describe the rational programming of function in a de novo designed di-iron carboxylate protein from the Due Ferri family. Originally created to catalyse the O2-dependent, two-electron oxidation of hydroquinones, the protein was reprogrammed to catalyse the selective N-hydroxylation of arylamines by remodelling the substrate access cavity and introducing a critical third His ligand to the metal-binding cavity. Additional second- and third-shell modifications were required to stabilize the His ligand in the core of the protein. These structural changes resulted in at least a 106-fold increase in the relative rate between the arylamine N-hydroxylation and hydroquinone oxidation reactions. This result highlights the potential for using de novo proteins as scaffolds for future investigations of the geometric and electronic factors that influence the catalytic tuning of di-iron active sites.
A Rhodium Complex-Linked β-Barrel Protein as a Hybrid Biocatalyst for Phenylacetylene Polymerization
Our group recently prepared a hybrid catalyst containing a rhodium complex, Rh(Cp)(cod), with a maleimide moiety at the peripheral position of the Cp ligand. This compound was then inserted into a β-barrel protein scaffold of a mutant of aponitrobindin (Q96C) via a covalent linkage. The hybrid protein is found to act as a polymerization catalyst and preferentially yields trans-poly(phenylacetylene) (PPA), although the rhodium complex without the protein scaffold normally produces cis PPA.
Artificial Copper Enzymes for Asymmetric Diels–AlderReactions
Artificial Dicopper Oxidase: Rational Reprogramming of Bacterial Metallo- b-lactamase into a Catechol Oxidase
Artificial Enzymes Based on Supramolecular ScaffoldsReview
Artificial Metalloenzymes as Catalysts in Stereoselective Diels–Alder ReactionsReview
Biotinylated Rh(III) Complexes in Engineered Streptavidin for Accelerated Asymmetric C–H Activation
Catalysis by a De Novo Zinc-Mediated Protein Interface: Implications for Natural Enzyme Evolution and Rational Enzyme Engineering
Computational Redesign of a Mononuclear Zinc Metalloenzyme for Organophosphate Hydrolysis
Creation of an Artificial Metalloprotein with a Hoveyda–Grubbs Catalyst Moiety through the Intrinsic Inhibition Mechanism of α-Chymotrypsin
Crystal Structure of Two Anti-Porphyrin Antibodies with Peroxidase Activity
Design and Evolution of Artificial Metalloenzymes: Biomimetic AspectsReview
Designing a Functional Type 2 Copper Center that has Nitrite Reductase Activity Within α-Helical Coiled Coils
Enantioselective Artificial Metalloenzymes by Creation of a Novel Active Site at the Protein Dimer Interface
Enantioselective Transfer Hydrogenation of Ketone Catalysed by Artificial Metalloenzymes Derived from Bovine β-Lactoglobulin
Incorporation of Manganese Complexes into Xylanase: New Artificial Metalloenzymes for Enantioselective Epoxidation
Organometallic Chemistry in Protein ScaffoldsReview