Molecular Design and Regulation of Metalloenzyme Activities through Two Novel Approaches: Ferritin and P450s

We have developed two novel approaches for the construction of artificial metalloenzymes showing either unique catalytic activities or substrate specificity. The first example is the use of a hollow cage of apo-ferritin as a reaction vessel for hydrogenation of olefins, Suzuki-Miyaura C-C coupling and phenylacetylene polymerization by employing Pd0 nano-clusters, Pd2+(η3-C3H5) complexes and Rh1+(nbd) (nbd = norbornadiene) complexes introduced in the hollow cage, respectively. The second approach is the use of “decoy molecules” to change substrate specificity of P450s, allowing epoxidation and hydroxylation activities toward nonnative organic substrates in P450SPα, P450BSβ and P450BM3 without the mutation of any amino acid. Finally, the decoy strategy has been applied to an in vivo system of P450, i.e., the use of P450BM3 expressed in the whole cell of E. coli to oxidize benzene to phenol.