Preparation, Characterization and Catalytic Activities of Immobilized Enzyme Mimics

Abstract

In order to find highly active and selective oxygen-transfer catalysts with appreciable durability, Cu(II)-histidine complexes were covalently grafted onto a chlorinated polystyrene resin as copper-containing enzyme mimics. The Cu(II)-histidine complexes and the mobile polymer were to resemble the active center and the proteomic skeleton of the enzymes, respectively. The resulting heterogenized complexes were expected to be nearly so active and more durable catalysts that are easier to recycle than their homogeneous counterparts. The substances were tested in a superoxide radical anion dismutation reaction. Control for the syntheses was exerted by protecting either the N-terminal or the C-terminal of the covalently grafted L-histidine molecules. During the preparative work generally applied methods of synthetic organic chemistry (alkylation or esterification) were used. Various anchored complexes were prepared and characterized by classical analytical methods, different forms of spectroscopy as well as molecular modeling. The covalently grafted complexes having the protected amino acids as ligands displayed remarkably high activities in the superoxide dismutase (SOD) test reaction.

Synthesis and formulation of functional bionanomaterials with superoxide dismutase activity

“…Besides, to replace the sensitive and hardly manageable native SOD, artificial enzymes composed of transition metal complexes or other inorganic substances of sufficient SOD-like activity were prepared and immobilized in/on silica, 45,46 montmorillonite, 47,48 carbon nanotube 49 and polymer 50 particles.…”

Immobilization of Superoxide Dismutase on Polyelectrolyte‐Functionalized Titania Nanosheets

“…[7] However,s upplementation of SOD is difficult owing to its high sensitivity to environmentalc onditions (e.g.,t emperature, pH, and complex nature in biofluids). Therefore, significante fforts have been made to prepare metal complexes, [8][9][10][11][12] nanoparticles or colloidalp articles, [13] or their combinations [14][15][16][17][18] to obtain artificial SOD materials of similara ctivity,b ut with improved sensitivity relative to that of the native enzyme.…”

CuII(Sal-Ala)/CuAlLDH Hybrid as Novel Efficient Catalyst for Artificial Superoxide Dismutase (SOD) and Cyclohexene Oxidation by H2O2

“…All materials, except the MgAlLDH support, displayed catalytic activity in the dismutation reaction of superoxide radical anions and their activity is comparable with and even better than other biomimetic copper complexes immobilized into different supports [8][9][10][11]. The inhibition (%) of different artificial SOD concentrations was calculated and the curves are shown in Fig.…”

“…Some of the synthetic metal complexes have shown to possess favorable SOD activity and enzyme mimicking. Thus, Cu II and Cu II -Zn II complexes were adsorbed on silica gel [8], montmorillonite [9] or grafted on different type of silica by ionic interactions [10] and on a chlorinated polystyrene resin [11], as well as tested for their SOD activity. The type of the support and the interactions between its surface and the active metal ions are very important parameters for superoxide scavenging activity.…”