Design and synthesis of redox or catalytically active artificial metalloproteins containing non-native inorganic and organometallic complexes

The design and synthesis of new proteins with novel binding and catalytic properties has been an active area of study for the past three decades. In an effort to expand the redox and catalytic activity of native proteins and to transform synthetic inorganic and organometallic complexes into environmentally benign asymmetric catalysts, we have covalently attached metal complexes, such as ferrocene and manganese salen (Mn(Salen)) to the active sites of cytochrome c peroxidase (CcP) and sperm whale myoglobin (Mb) using cysteine residues. The new metalloproteins were characterized by UV-Vis, CD, electrospray mass spectroscopy and cyclic voltammetry. Together with chemical reactivity studies, these results demonstrated that the encapsulation of metal complexes by CcP and Mb have led to singly and reversibly modified enzymes that are catalytically and redox active in aqueous solution. The significance of these results regarding protein design, green chemistry and asymmetric catalysis is discussed.