Recombinant Betula pendula Peroxidase 2
Description
Biochemical Properties and Function
Peroxidases are heme-containing enzymes that catalyze the oxidation of substrates using hydrogen peroxide (H₂O₂) as an electron acceptor. In plants, they play critical roles in lignin biosynthesis, stress responses, and antioxidant defense.
Key Attributes of rBpPrx2:
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Active Site: Likely contains a ferriprotoporphyrin IX heme group, typical of plant peroxidases .
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Substrate Specificity: Expected to oxidize phenolic compounds (e.g., guaiacol, syringaldazine) and monolignols, similar to Arabidopsis peroxidases .
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Stress Response: Elevated guaiacol peroxidase activity in B. pendula under traffic pollution (e.g., NOₓ exposure) suggests a role in mitigating oxidative stress .
| Enzyme Attribute | Observed in Related Peroxidases |
|---|---|
| Substrate oxidation | Syringaldazine, guaiacol |
| Heme group | Ferriprotoporphyrin IX |
| Stress response | Upregulated under NOₓ exposure |
Production and Purification
Recombinant production typically involves heterologous expression in E. coli or yeast. For example, Arabidopsis peroxidases (AtPrx2, AtPrx25) were refolded from inclusion bodies using optimized buffer conditions . A similar approach could apply to rBpPrx2:
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Refolding: Requires careful adjustment of urea/guanidine concentrations, hemin, and redox agents (e.g., GSSG/GSH) .
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Purification: Ion exchange chromatography (MonoS/Q columns) or hydrophobic interaction chromatography .
| Production Parameter | Optimal Condition |
|---|---|
| Denaturant | Urea (for AtPrx25) |
| Refolding pH | Neutral to alkaline |
| Purification method | Ion exchange |
Environmental Stress Mitigation
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Pollution Tolerance: B. pendula exhibits enhanced guaiacol peroxidase activity under traffic-induced NOₓ exposure, suggesting rBpPrx2 could contribute to detoxifying reactive oxygen species (ROS) .
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Lignification: Likely involved in cell wall lignin polymerization, similar to Arabidopsis peroxidases .
Medical and Biotechnological Potential
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Antioxidant Activity: Betulin and polyphenols in B. pendula extracts show neuroprotective effects against amyloid-β toxicity , a trait potentially linked to peroxidase-mediated ROS scavenging.
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Wound Healing: Birch extracts (e.g., Episalvan gel) are used in dermatology , possibly leveraging peroxidase activity to modulate tissue repair.
Future Directions
Research gaps include:
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Direct characterization of rBpPrx2’s enzymatic activity and stability.
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Exploring its interaction with pollutants like particulate matter (PM) and nitrogen dioxide (NO₂) .
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Investigating its role in B. pendula’s ability to thrive in urban environments .
References: Air pollution effects on B. pendula pollen allergenicity. Arabidopsis peroxidase catalytic profiles. Guaiacol peroxidase activity in B. pendula under traffic stress. Pharmacological properties of B. pendula leaf extracts. Traditional and medical uses of B. pendula.
