Immobilization of Recombinant Human Catalase on Gold and Silver Nanoparticles

Abstract

Human catalase cDNA was cloned into a pEX-C-His vector. Purified recombinant catalase was immobilized on nanoparticles. Gold and silver nanoparticles were synthesized in a variety of sizes by chemical reduction; no agglomerates or aggregates were observed in any of the colloids during dynamic light scattering or scanning transmission electron microscopy analysis. After immobilization on gold nanoparticles, recombinant catalase activity was found to be lower than that of the same amount of enzyme in aqueous solution. However, after 10 days of storage at room temperature, the activity of catalase immobilized on gold nanoparticles (AuNPs) of 13 and 20 nm and coverage of 133% was 68 and 83% greater than catalase in aqueous solution, respectively. During 10 days of experiment, percentage activity of catalase immobilized on those gold nanoparticles was higher in comparison to CAT in aqueous solution. Catalase immobilized on silver nanoparticles did not lose activity as significantly as catalase immobilized on AuNPs. Those results confirm the ability to produce recombinant human enzymes in a bacterial expression system and its potential use while immobilized on silver or gold nanoparticles.

Interaction of silver nanoparticles with antioxidant enzymes

“…A significant time effect was observed with a decrease of the activity of CAT to 60.8 ± 3.3% from the initial level after 24 h. The above observation is consistent with the existing literature showing that CAT activity decreases after interacting with TiO 2 NPs, 16 magnetic nanoparticles, 42 or AuNPs. 43,44 Indeed, changes in the CAT structure could be responsible for the initial changes in the activity we observed. However, they contrast with the findings that the activity of CAT was unchanged 44 or increased in AgNP treatments.…”

Facile synthesis of SnO2shell followed by microwave treatment for high environmental stability of Ag nanoparticles

“…The AgNPs used in this work were synthesized by a two-step method with an intermediate seed stage, which has been described in detail in our previous reports. 22,23 The nanoparticles were characterized by a hydrodynamic diameter of about 20 nm using DLS analysis (Fig. S3 †).…”

The Role of microRNAs in Metabolic Syndrome-Related Oxidative Stress

“…GPxs reduce lipid hydroperoxides to their corresponding alcohols as well as mediate breakdown of H2O2 to water. CAT, located mainly in peroxisomes, also mediates decomposition of H2O2 to water and oxygen [39,40]. GR catalyzes the reduction of glutathione disulfide (GSSG) to the sulfhydryl form of glutathione (GSH), which is a critical molecule in resisting OxS, maintaining the reducing environment of the cell and its proper function.…”

“…In addition, it plays a key role in the metabolism and clearance of xenobiotics, acts as a cofactor in certain detoxifying enzymes, participates in transport, and regenerates antioxidants such as vitamins E and C to their reactive forms [41]. CAT catalyzes the decomposition of H2O2 to water and oxygen, it contains four iron-containing heme groups that allow the enzyme to react with the H2O2 and is usually located in a cellular organelle called the peroxisome, whose major function is the breakdown of very long chain fatty acids through β-oxidation [39,40].…”