Nanostructures for peroxidases

Abstract

Peroxidases are enzymes catalyzing redox reactions that cleave peroxides. Their active redox centers have heme, cysteine thiols, selenium, manganese, and other chemical moieties. Peroxidases and their mimetic systems have several technological and biomedical applications such as environment protection, energy production, bioremediation, sensors and immunoassays design, and drug delivery devices. The combination of peroxidases or systems with peroxidase-like activity with nanostructures such as nanoparticles, nanotubes, thin films, liposomes, micelles, nanoflowers, nanorods and others is often an efficient strategy to improve catalytic activity, targeting, and reusability.

Keywords: antioxidant enzymes; antioxidants; improved and reusable peroxidase activity; micelles; nanotubes; particles; self-assembly.

Figure 1

Structural diversity of peroxidases and their redox centers. (A) The glutathione peroxidase (1GP1-SeH) monomer and its selenium cysteine SeCys-35 (Epp et al., 1983). (B) The manganese peroxidase (1YYD) monomer from Phanerochaete chrysosporium and its heme iron plus Mn³⁺ (Sundaramoorthy et al., 2005). (C) The dimeric catalase (1DGB) structure from human erythrocytes and its heme iron (Putnam et al., 2000). (D) The decameric peroxiredoxin (1QMV) from human erythrocytes and its cysteine thiol residues (Schröder et al., 2000). The PDB ID for each protein is inbetween parentheses.

Figure 2

Nanostructures for immobilizing and reusing peroxidases. (A) Entrapment of HRP in inorganic matrix of flowers like nanomaterial (Wang et al., 2014). (B) Covalent attachment of HRP on NH₂ –modified Fe₃O₄/SiO₂ magnetic nanoparticles (Chang and Tang, 2014).