A General Method for Artificial Metalloenzyme Formationthrough Strain-Promoted Azide–Alkyne Cycloaddition
Strain‐promoted azide–alkyne cycloaddition (SPAAC) can be used to generate artificial metalloenzymes (ArMs) from scaffold proteins containing a p‐azido‐L‐phenylalanine (Az) residue and catalytically active bicyclononyne‐substituted metal complexes. The high efficiency of this reaction allows rapid ArM formation when using Az residues within the scaffold protein in the presence of cysteine residues or various reactive components of cellular lysate. In general, cofactor‐based ArM formation allows the use of any desired metal complex to build unique inorganic protein materials. SPAAC covalent linkage further decouples the native function of the scaffold from the installation process because it is not affected by native amino acid residues; as long as an Az residue can be incorporated, an ArM can be generated. We have demonstrated the scope of this method with respect to both the scaffold and cofactor components and established that the dirhodium ArMs generated can catalyze the decomposition of diazo compounds and both SiH and olefin insertion reactions involving these carbene precursors.
An Artificial Metalloenzyme: Creation of a Designed Copper Binding Site in a Thermostable Protein
Guided by nature: A designed binding site comprising the His/His/Asp motif for CuII complexation has been constructed in a robust protein by site‐specific mutagenesis (see picture). The artificial metalloenzyme catalyzes an enantioselective Diels–Alder reaction.