An Artificial Di-Iron Oxo-Orotein with Phenol Oxidase Activity
Here we report the de novo design and NMR structure of a four-helical bundle di-iron protein with phenol oxidase activity. The introduction of the cofactor-binding and phenol-binding sites required the incorporation of residues that were detrimental to the free energy of folding of the protein. Sufficient stability was, however, obtained by optimizing the sequence of a loop distant from the active site.
Notes: kcat/KM ≈ 1380 M-1*min-1
Aqueous Oxidation of Alcohols Catalyzed by Artificial Metalloenzymes Based on the Biotin–Avidin Technology
Based on the incorporation of biotinylated organometallic catalyst precursors within (strept)avidin, we have developed artificial metalloenzymes for the oxidation of secondary alcohols using tert-butylhydroperoxide as oxidizing agent. In the presence of avidin as host protein, the biotinylated aminosulfonamide ruthenium piano stool complex 1 (0.4 mol%) catalyzes the oxidation of sec-phenethyl alcohol at room temperature within 90 h in over 90% yield. Gel electrophoretic analysis of the reaction mixture suggests that the host protein is not oxidatively degraded during catalysis.
Max TON: 200ee: ---PDB: ---Notes: ---
Host protein: Avidin (Av)Max TON: 230ee: ---PDB: ---Notes: ---
Max TON: 173ee: ---PDB: ---Notes: ---
Metal: RhMax TON: 7.5ee: ---PDB: ---Notes: ---
De Novo Design of Catalytic Proteins
The de novo design of catalytic proteins provides a stringent test of our understanding of enzyme function, while simultaneously laying the groundwork for the design of novel catalysts. Here we describe the design of an O2-dependent phenol oxidase whose structure, sequence, and activity are designed from first principles. The protein catalyzes the two-electron oxidation of 4-aminophenol (k cat/K M = 1,500 M·1·min·1) to the corresponding quinone monoimine by using a diiron cofactor. The catalytic efficiency is sensitive to changes of the size of a methyl group in the protein, illustrating the specificity of the design.