Characterisation of an anionic peroxidase from horseradish cv. Balady

Development of chia gum/alginate-polymer support for horseradish peroxidase immobilization and its application in phenolic removal

Chia gum's molecular structure with distinctive properties as well as the alginate-based hydrogel's three-dimensionally cross-linked structure can provide a potent matrix for immobilization of enzyme. Herein, chia gum (CG)/alginate (A)-polymeric complex was synthesized and employed as a support material for the immobilization of horseradish peroxidase (HRP). HRP was successfully immobilized on the developed ACG-polymeric support, and the highest immobilization recovery (75%) was observed at 1.0% CG and 2% A, pH 7.0, and 50 units of the enzyme. The structure, morphology, and thermal properties of the prepared ACG-HRP were demonstrated using Fourier Transform Infrared (FTIR), Scanning Electron Microscope, and Thermogravimetric (TGA) analyses. ACG-HRP showed a good reusability (60%) over ten reuses. The immobilized ACG-HRP displayed an acidic pH optimum (6.0), a higher temperature optimum (50 °C), and improved thermal stability (30-50 °C) compared to the soluble HRP at pH 7.0, 40 °C and (30-40 °C), respectively. ACG-HRP has a lower affinity for hydrogen peroxide (H2O2) and guaiacol and a higher oxidizing affinity for a number of phenolic substrates. The ACG-HRP demonstrated greater resistance to heavy metals, isopropanol, urea, Triton X-100, and urea, as well as improved efficiency for eliminating phenol and p-chlorophenol. The developed ACG-polymeric support provided improved enzyme properties, allowed the reuse of the immobilized HRP in 10 cycles, and made it promising for several biotechnological applications.

Immobilization of horseradish peroxidase on cationic microporous starch: Physico-bio-chemical characterization and removal of phenolic compounds

In the present study, two different modified starches; microporous starch (MPS) and cationic microporous starch (CMPS) were synthesized. The granules of MPS that distributed regularly were destroyed after the etherification reaction. The data depicted that the immobilization of horseradish peroxidase (HRP) on CMPS revealed highest immobilization efficiency (86%) at 100 mg of CMPS at pH = 6.0 and 100 units of enzyme. After 10 reuses of the CMPS-HRP, it retained 66% of initial activity. The soluble HRP showed broad pH optimum of 6.0-7.0, which changed to sharp pH = 6.0 for CMPS-HRP. Soluble-HRP and CMPS-HRP showed temperature optima at 30 °C and 40 °C, respectively. The CMPS-HRP showed high thermal stability up to 50 °C compared to the soluble HRP (40 °C). The Km values of soluble HRP and CMPS-HRP were 6.6 and 10.8 mM for H₂O₂ and 34 and 41.6 mM for guaiacol, respectively. CMPS-HRP showed higher affinity toward various substrates than the soluble-HRP. CMPS-HRP showed more resistance against heavy metals, urea, isopropanol, Triton X-100 and trypsin than soluble enzyme. The CMPS-HRP showed higher ability to remove phenol and p-chlorophenol compared to soluble-HRP.

Purification and characterization of cationic peroxidase from ginger (Zingiber officinale)

Background

Due to versatility in reaction catalyzed by peroxidases, they have potential applications in different areas in the health sciences, food industry, and diagnostic purposes. Therefore, the aim of this study is to investigate the properties of peroxidase from ginger to be meeting the perquisites of several applications.

Results

The cationic peroxidase (GPII) was purified to homogeneity by anion exchange chromatography using DEAE–Sepharose column followed by cation exchange chromatography using CM–Sepharose column and finally Sephacryl S-200 column. The molecular mass of GPII was 42 kDa. GPII shows oxidizing activity with several phenolic compounds by using H2O2 as the second substrate. The natural plant phenolic compounds as pyrogallol, catechol, and guaiacol were found to be excellent electron donors for the enzyme compared to other phenolic compounds. GPII exhibited Km values of 3.1 and 7.1 mM and Vmax values of 0.6 and 0.31 units/assay using H2O2 and guaiacol as substrates, respectively. The enzyme exhibited maximal peroxidase activity at broad pH’s 6.0–7.5 and 50 °C. GPII was thermal stable up to 50 °C and retained 66% of its activity at 70 °C after 1 h incubation. The GPII activated by most divalent cations tested and inhibited by Hg2+ and Cu2+ cations.

Conclusion

PGII could be used in several applications due to its catalytic properties, thermal stability, broad pH, and acting on several phenolic compounds.

Purification and characterization of peroxidases from garden cress sprouts and their roles in lignification and removal of phenol and p-chlorophenol

The study aims to evaluate the relation between peroxidases of day-6 garden cress sprouts and phenolic compounds. Three cationic, three anionic, and two unbounded peroxidases were separated from day-6 garden cress sprouts. Cationic (GCP1) and anionic (GCP2) peroxidases were purified with molecular masses of 25 and 40 kDa, respectively. The K_m values of GCP1 toward H₂ O₂ and guaiacol were lower than GCP2. The anionic GCP2 exhibited high affinity toward some lignin monomers, sinapyl alcohol, coniferyl alcohol, cinnamic and ferulic acids. Therefore, GCP2 is considered as a lignin peroxidase and contributed in lignin synthesis. The activity of GCP1 and GCP2 was stable at a wide pH range 5.5-8.0 and 6.0-7.5, respectively. Both peroxidases showed the same thermal stability range 20-50°C. GCP2 was more resistant against the effect of metal ions than GCP1. GCP2 showed high ability to remove of phenol and p-chlorophenol from effluent compared to GCP1. PRACTICAL APPLICATIONS: Generally, garden cress is used as a test plant to conduct biomonitoring of pollution in urban soil on a wide scale because of its simplicity, sensitivity, and cost-effectiveness. Peroxidase is an important antioxidant enzyme, which elevated when plant subjected to pollution. Recently, we reported that the increase of peroxidase activity was strongly correlated with high phenolic content and antioxidant activity during the germination of garden cress. In the present study, anionic peroxidase GCP2 may play an important role in lignification process and removal of phenol and p-chlorophenol from polluted soil/wastewater as well as resisted the harmful effect of heavy metals. Cationic peroxidase GCP1, as a natural scavenger, had high affinity toward H₂ O₂ coupled to oxidation of some plant phenolic compounds suggesting its role in consuming of excess H₂ O₂ .

A novel peroxidase from Ziziphus jujuba fruit: purification, thermodynamics and biochemical characterization properties

In this study, peroxidase from Ziziphus jujuba was purified using ion exchange, and gel filtration chromatography resulting in an 18.9-fold enhancement of activity with a recovery of 20%. The molecular weight of Z. jujuba peroxidase was 56 kDa, as estimated by Sephacryl S-200. The purity was evaluated by SDS, which showed a single prominent band. The optimal activity of the peroxidase was achieved at pH 7.5 and 50 °C. Z. jujuba peroxidase showed catalytic efficiency (Kcat/Km) values of 25 and 43 for guaiacol and H₂O₂, respectively. It was completely inactivated when incubated with β-mercaptoethanol for 15 min. Hg²⁺, Zn²⁺, Cd²⁺, and NaN3 (5 mM) were effective peroxidase inhibitors, whereas Cu²⁺ and Ca²⁺ enhanced the peroxidase activity. The activation energy (Ea) for substrate hydrolysis was 43.89 kJ mol⁻¹, while the Z value and temperature quotient (Q₁₀) were found to be 17.3 °C and 2, respectively. The half-life of the peroxidase was between 117.46 and 14.15 min. For denaturation of the peroxidase, the activation energy for irreversible inactivation Ea*(d) was 120.9 kJmol⁻¹. Thermodynamic experiments suggested a non-spontaneous (∆G*d > 0) and endothermic reaction phase. Other thermodynamic parameters of the irreversible inactivation of the purified enzyme, such as ∆H* and ∆S*, were also studied. Based on these results, the purified peroxidase has a potential role in some industrial applications.

Encapsulation of HRP Enzyme onto a Magnetic Fe3O4 Np–PMMA Film via Casting with Sustainable Biocatalytic Activity

Horseradish peroxidase (HRP) enzyme was effectively encapsulated onto an Fe3O4 nanoparticle–polymethyl methacrylate (PMMA) film via the casting method. The HRP was immobilized on the 0.5% Fe3O4Np–PMMA film and characterized by Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Moreover, the reusability, thermal stability, optimum pH, optimum temperature, the influence of metal ions, and the effects of detergent and organic solvent were investigated. After optimizing the immobilization conditions, the highest efficiency of the immobilized enzyme was 88.4% using 0.5% Fe3O4Np–PMMA. The reusability of the immobilized HRP activity was 78.5% of its initial activity after being repeatedly used for 10 cycles. When comparing the free and immobilized forms of the HRP enzyme, changes in the optimum temperature and optimum pH from 30 to 40 °C and 7.0 to 7.5, respectively, were observed. The Km and Vmax for the immobilized HRP were estimated to be 41 mM, 0.89 U/mL for guaiacol and 5.84 mM, 0.66 U/mL for H2O2, respectively. The high stability of the immobilized HRP enzyme was obtained using metal ions, a high urea concentration, isopropanol, and Triton X-100. In conclusion, the applicability of immobilized HRP involves the removal of phenol in the presence of hydrogen peroxide, therefore, it could be a potential catalyst for the removal of wastewater aromatic pollutants.

Peroxidase as a simultaneous degradation agent of ochratoxin A and zearalenone applied to model solution and beer

The aim of this study was to evaluate the action of the commercial peroxidase (POD) enzyme (Armoracia rusticana) on the simultaneous degradation of ochratoxin A (OTA) and zearalenone (ZEA) in model solution and beer. For this purpose, the reaction parameters for POD action were optimized, POD application in the degradation of mycotoxins in model solution and beer was evaluated and the kinetic parameters of POD were defined (Michaelis-Menten constant - K_M and maximal velocity - V_max). In the reaction conditions (pH 7, ionic strength of 25 mM, incubation at 30 °C, addition of 26 mM H₂O₂ and 1 mM potassium ion), POD (0.6 U mL^-1) presented the maximum activity for simultaneous degradation of OTA and ZEA of 27.0 and 64.9%, respectively, in model solution after 360 min. The application of POD in beer resulted in the simultaneous degradation of OTA and ZEA of 4.8 and 10.9%, respectively. The kinetic parameters K_M and V_max for degradation of OTA and ZEA were 50 and 10,710 nM and 0.168 and 72 nM min^-1, respectively. Therefore, POD can be a promising alternative to mitigate the contamination of OTA and ZEA in model solution and beer, minimizing their effects in humans.

Peroxidase from Coleus Forskohlii: Purification and Biochemical Characterization

In this study, a peroxidase from new source was purified using ion exchange and gel filtration techniques. The recovery for peroxidase activity was 19% with 11-fold purification and specific activity of 749 unit/mg protein. Purified peroxidase demonstrated a molecular mass of 39 kDa using gel filtration and was confirmed as a single band on SDS-PAGE. The purified peroxidase revealed a broad optimum pH activity at 6.0-6.5 and 50°C temperature. The kinetic parameters for purified peroxidase toward H2O2 and guaiacol as substrates were found to be Km = 3.355, 5.395 mM, Kcat = 99.52, 79.56 s-1 and Vmax =1.531, 1.242 µmole ml-1 min-1, respectively. The catalytic efficiency (kcat/Km) of the purified peroxidase was 14.75 and 29.66 s−1 mM−1 for guaiacol and H2O2, respectively. Peroxidase activity was observed to be enhanced by Cu2+, Co2+, Ni2+ and inhibited in the presence of Sn2+, Al3+, Hg2+, NaN3, EDTA and urea. Characterization showed that peroxidase purified from C. forskohlii has the ability to be used for food industrial applications.

Amidrazone modified acrylic fabric activated with cyanuric chloride: A novel and efficient support for horseradish peroxidase immobilization and phenol removal

In this study, hydrazine treated acrylic fabrics (polyacrylonitrile, PAN) activated with cyanuric chloride was developed as supporting material for horseradish peroxidase (HRP) immobilization. The immobilization of HRP onto the modified supporting material was achieved after being end-over-end incubated for 12 h. Field emission scanning electron microscopy and Fourier-transform infrared spectroscopy techniques were used to confirm the successful immobilization. Reusability experiment was performed to estimate the ability of the immobilized HRP to recover the reaction medium, in which it was observed to retain 78% of its original activity after 10 cycles. Relative to the soluble HRP, the optimum pH and temperature for the immobilized HRP were shifted to 7-7.5 and 50 °C, respectively. The kinetic parameters of guaiacol and H₂O₂ for the immobilized HRP were determined to be Km/Vmax = 57.61, 11.35 and Kcat/Km = 1.87, 1.86, respectively, while the values for the free form were Km/Vmax = 41.49, 6.23 and Kcat/Km = 1.87, 1.86, respectively. Compared to the soluble form, the immobilized HRP exhibited higher resistance toward metal ions and some organic solvents. For an application perspective. The immobilization of HRP using this procedure has the potential to be used for industrial application and wastewater treatment.

Immobilization of horseradish peroxidase on PMMA nanofibers incorporated with nanodiamond

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 H₂O₂ 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.

Concanavalin A photocross-linked affinity cryogels for the purification of horseradish peroxidase

The present study describes an easy and efficient procedure for the purification of horseradish peroxidase from horseradish roots. For this purpose, supermacroporous cryogels having Concanavalin A were prepared by photosensitive cross-linking polymerization. Horseradish peroxidase binding and elution from the prepared cryogels were carried out changing various parameters such as initial peroxidase concentration and pH. The best binding performance was obtained at pH 7.0. The maximum horseradish peroxidase binding of the cryogels was found to be 3.85 mg g−1 cryogel. Horseradish peroxidase purification from crude extract resulted in 115.1-fold. SDS-PAGE analysis and circular dichroism measurements indicated that the horseradish peroxidase purification from horseradish roots was successfully carried out.

Purification and characterization of peroxidase from sprouted green gram (Vigna radiata) roots and removal of phenol and p-chlorophenol by immobilized peroxidase

BACKGROUND

Peroxidase activity was increased during germination of green gram and such an increase may have benefits in many physiological processes. The present study aimed to investigate the optimum conditions for the extraction, purification and characterization of peroxidase from the germinated green gram roots and also its application for the removal of phenols in water.

RESULTS

Peroxidase activity was increased by 300-fold in 5-day germinated green gram. Because the root was rich in peroxidase activity, peroxidase from roots was isolated and purified to homogeneity. The purified peroxidase showed a single band on sodium dodecyl sulphate-polyacrylamide gel electrophoresis with a molecular weight of 50 kDa, an optimum pH of 5.5 and a pH stability ranging from 5 to 9. The enzyme had 50% residual activity at 70 °C. It catalyzed the oxidation of a variety of substrates. The K_m value of the enzyme was 1.28 mmol L^-1 for o-dianisidine and 0.045 mmol L^-1 for H₂ O₂ . The enzyme lost 100% activity in the presence of dithiothreitol and cysteine. The addition of copper ion increased the enzyme activity by three-fold. Both soluble and immobilized peroxidases removed more phenol than p-chlorphenol, whereas horseradish peroxidase removed more p-chlorphenol. Thus, the green gram root peroxidase showed good pH and temperature stability, as well as the ability to remove phenolic compounds from effluent.

CONCLUSION

Peroxidase with good thermal and pH stability was purified from germinated green gram roots and has the ability to oxidize phenolic compounds from waste water. © 2016 Society of Chemical Industry.

Comparative analysis of peroxidase profiles in Chinese kale (Brassica alboglabra L.): evaluation of leaf growth related isozymes

Plant peroxidases (EC 1.11.1.7) with different isoforms catalyze various reactions in plant growth and development. However, it is difficult to elucidate the function of each isozyme in one plant. Here, we compared profiles of entire isozyme in young seedling and mature leaves of Chinese kale (Brassica alboglabra L.) on zymogram and ion exchange chromatography in order to investigate leaf growth related peroxidase isozymes. The results showed that four isozymes were constitutively expressed in kale leaves, whereas other two isozymes were induced in the mature leaves. The Mono Q ion exchange chromatography separated the six isozymes into two major groups due to the difference in their isoelectric points. The results suggested that although there were several isozymes in the leaves of Chinese kale, one isozyme functioned mainly through the leaf development. Two anionic isozymes with molecular weights lower than 32 kDa were considered mature related.