Iron‐Porphyrin/Cysteine/PEG as Pseudo‐Chloroperoxidase Nanozyme

AbstractPorphyrins can be widely used as active‐site biocomplexes, where biomimetic synthetic metal porphyrin is considered as being pseudo‐enzyme. The system consisted of porphyrin‐metal‐cysteine (Cys) complex and PEG polymer or mixed SDS/DTAB surfactants has used to model native chloroperoxidase (CLP). Metal‐tetra(2‐pyridyl)porphyrins (M‐TPP) as more potent than heme (native active‐site) were designed and synthesized based on lowering Michaeilis‐Menten parameter. Fe‐TTP has the maximum CLP activity among central metal including iron(+3), manganese(+3) and zinc(+2). Triple‐component: Fe‐TPP/Cys/PEG, indicated most efficient “nanozyme” toward native CLP efficiency. It can be seen that porphyrin hydrophobicity varies by changing central metal, detected via Thioflavin T fluorescence method such as Fe(+3)> Mn(+3)> Zn(+2) attributed to charge transfer between π‐electron and central metal. Dynamic light scattering indicates that the addition of Fe‐TPP/Cys, as PEG absorbent nucleus, causes nano‐particle creation. Transmission electron microscopy illustrated multi‐holes vesicular Fe‐TPP/Cys/PEG nanozyme that causes more efficiency via higher specific surface area for substrate trap comparing one‐hole vesicular Fe‐TPP/Cys/SDS/DTAB biocatalyst. Presence of Fe‐TPP/Cys active‐site inside nanozyme was confirmed by UV‐Visible spectroscopy as well as Circular dichroism. Differential scanning calorimetry indicates more single colloid structure for PEG nanozyme than attributed SDS/DTAB biocatalyst.