Vesicular mixed gemini-SDS-hemin-imidazole complex as a peroxidase-like nano artificial enzyme.

A biomimetic was designed for the construction of a new efficient peroxidase-like nano artificial enzyme with a heme-imidazole component complexed with gemini 12-2-12/SDS supramolecules. The presence of a simple surfactant mixture (SDS/gemini 12-2-12 at a particular concentration) provided an apoprotein-like hydrophobic pocket for the heme-imidazole moiety, which produced a peroxidase active site containing positive and negative charges distributed on the colloidal surface. Vesicular structures that stabilized the heme-imidazole complexes formed multienzyme advanced colloids. The enzymatic activation parameters indicated that the catalytic efficiency of the novel nano artificial enzyme was 27% as efficient as the native horseradish peroxidase (HRP). The imidazole moiety, which functionally corresponded to the histidine ligand in the native HRP, increased the reactivity and catalytic efficiency of the artificial enzyme. The nano biocatalyst did not exhibit suicide inactivation until high concentrations of hydrogen peroxide, indicating that the vesicle hydrophobic pocket effectively shielded the active site, thereby controlling the concentration of hydrogen peroxide at the heme moiety and enabling high rates of enzymatic turnover.