[Catalytic properties and stability of horseradish peroxidase immobilized in polyacrylamide gel].
Authors: Ugarova, Kershengol'ts, Artamonov, Berezin
Journal: Biokhimiia (Moscow, Russia)
Summary
Horseradish peroxidase immobilised within polyacrylamide gel matrices retains catalytic characteristics broadly comparable to its free form, though with notable compromises: substrate affinity (Km) and pH-response curves remained similar, yet turnover rate (kcat) declined threefold at pH 7.0. Researchers assessed both pH stability at 20°C and thermal stability across 20–81°C for soluble and immobilised enzyme preparations, revealing that the gel environment substantially compromised peroxidase longevity—a threefold reduction in stability at ambient temperature escalated to a seventeenfold decline at 56°C. For equine practitioners considering enzyme-based diagnostic or therapeutic applications, these findings suggest that whilst gel immobilisation preserves substrate recognition and pH operating windows, the accompanying loss of catalytic efficiency and accelerated degradation under physiological temperatures would necessitate either supplemented enzyme concentrations or alternative stabilisation strategies to maintain clinical utility.
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Practical Takeaways
- •This study has no direct application to equine practice; it is fundamental biochemistry research on enzyme immobilization techniques
Key Findings
- •Horseradish peroxidase immobilized in polyacrylamide gel showed Km and pH-dependency similar to soluble enzyme, but kcat was 3-fold lower at pH 7.0
- •Stability of immobilized peroxidase decreased 3-fold at 20°C and 17-fold at 56°C compared to soluble enzyme
- •pH-stability profiles of immobilized and soluble peroxidase differed across the temperature range tested (20-81°C)