A peroxidase coordinating to Zn (II) preventing heme bleaching and resistant to the interference of H₂O₂

Abstract

Dehaloperoxidase (DHP) catalyzes detoxifying halophenols. It is a heme-containing enzyme using H 2 O 2 as the oxidant. Heme bleaching from the active site is of great concern. In addition, the interference of DHP by H 2 O 2 leads to the inactivation of the enzyme. To solve these two problems, DHP is coordinated to Zn (II) in PBS buffer to form a biomineralized composite (DHP&Zn-CP). DHP&Zn-CP was characterized by measuring SEM and confocal images, as well as energy dispersive X-ray spectrometry mapping. Fluorescence spectra demonstrated that DHP&Zn-CP can prevent heme bleaching. Two-dimensional FTIR spectra were measured, dynamically providing insight into the structural change of DHP along the coordination process. Raman spectra were performed to analyze the structural change. The optical spectra confirmed that the forming of DHP&Zn-CP had a little effect on the structures of DHP. For the dehalogenation of 2,4,6-trichlorophenol, DHP&Zn-CP can tolerate the presence of H 2 O 2 and is resistant to the interference by H 2 O 2. The catalytic efficiency of DHP&Zn-CP is much higher than that of free DHP.