Enhancement of peroxidase activity in the artificial Mimochrome VI catalysts through rational design

Rational design provides an attractive strategy to tune and control the reactivity of bioinspired catalysts. While there has been considerable progress in the design of heme oxidase mimetics with active site environments of ever-growing complexity and catalytic efficiency, their stability during turnover is still an open challenge. Here we show that the simple incorporation of two 2-amino isobutyric acids into an artificial peptide-based peroxidase resulted in a new catalyst (FeIII-MC6*a), with higher resistance against oxidative damage, and higher catalytic efficiency. A two-fold enhancement of the turnover number, respect to its predecessor, was observed. These results point out the protective role exerted by the peptide matrix and pave the way to the synthesis of robust bioinspired catalysts.