Immobilization of horseradish peroxidase on PMMA nanofibers incorporated with nanodiamond

Abstract

In the present study, nanodiamond (ND) was blended with polymethyl methacrylate (PMMA) and then electrospun into nanofibers (nfPMMA-ND) for the immobilization of horseradish peroxidase (HRP). The maximum immobilization efficiency of HRP (96%) was detected at 10% ND and pH 7.0. ATR-FTIR, SEM and TEM were used to characterize the immobilized enzyme. The immobilized enzyme retained 60% of its initial activity after ten reuses. The pH was shifted from 7.0 for soluble HRP to 7.5 for the immobilized enzyme. The soluble HRP had an optimum temperature of 30 C, whereas this temperature was shifted to 40 C for the immobilized enzyme. The substrate analogs were oxidized by immobilized HRP with higher efficiencies than those of soluble HRP. The kinetic results showed that the soluble HRP had more affinity toward guiacol and H 2 O 2 than immobilized HRP. The effect of metal ions on soluble and immobilized HRP was studied. The immobilized HRP was markedly more stable when it exposed to urea, isopropanol, butanol and heptane compared with the soluble enzyme. The immobilized HRP exhibited high resistance to proteolysis by trypsin than that of soluble enzyme. In conclusion, the nfPMMA-ND-HRP could be employed in several applications such as biosensor, biomedical and bioremediation.

Highly Selective Entrapment of His-Tagged Enzymes on Superparamagnetic Zirconium-Based MOFs with Robust Renewability to Enhance pH and Thermal Stability

“…Enzyme is a kind of powerful biocatalyst evolved from nature. The vigorous development of biotechnology represented by enzyme catalysis has brought new opportunities for the sustainable development of the chemical industry. , As a highly efficient biocatalyst, natural enzymes have excellent specificity of the substrate, selectivity, and eco-friendly reaction conditions, imposing important impacts on biocompatibility, biodegradability, and renewability. , Although the stability of enzymes has been improved through protein engineering, the sensibility of enzymes leads to the lack of catalytic activity under extreme conditions. , In addition, a large amount of free enzymes cannot be recovered after the reaction, which remains a major difficulty in industrial production. , Hence, immobilized enzymes have been confirmed to be a useful strategy to improve the activity, stability, and selectivity of enzymes to achieve wider applications in the biochemical and medical industries. − …”

Biocatalytic System Made of 3D Chitin, Silica Nanopowder and Horseradish Peroxidase for the Removal of 17α-Ethinylestradiol: Determination of Process Efficiency and Degradation Mechanism

“…As observed, the highest removal efficiency of estrogen was noted at 32.4 • C, 39.4 • C, and 49.9 • C for free HRP, HRP immobilized onto PAA/PVA nanofibers, and HRP immobilized onto nanofibers with Fe 3 O 4 , respectively. Furthermore, it was observed that the removal of estrogen by immobilized biomolecules was significantly higher than after the process using free HRP at the entire investigated temperature range, which could be explained by the fact that support materials protect HRP against high-temperature-induced deactivation [56]. Surprisingly, in our research, the most suitable temperature for the most effective EE2 removal has been determined as 25 • C. In these conditions, the following three biocatalytic systems allowed us to remove 100% of EE2 from aqueous solutions: (i) nanoSiO 2 (HRP)-pure chitin, (ii) pure nanoSiO 2 -chitin(HRP), (iii) nanoSiO 2 (HRP)-chitin(HRP).…”

Recent Advances in Enzymes for the Bioremediation of Pollutants

“…Many techniques have been utilized to immobilize and enhance the efficacy of enzyme by nanotechnology [57][58][59].…”