The Influence of Isoenzyme Composition and Chemical Modification on Horseradish Peroxidase@ZIF-8 Biocomposite Performance

Many articles in the literature deal with horseradish peroxidase (HRP) biomineralization, but none pay attention to the isoenzyme composition of commercial HRP or the influence of the carbohydrate component of the protein molecule on the biomineralization process. To study the impact of these factors, we performed periodate oxidation of commercial HRP and a purified HRP-C isoform for biomineralization within ZIF-8. With purified HRP, enzyme@ZIF-8 biocomposites with higher activity were obtained, while periodate oxidation of the carbohydrate component of both commercial HRP and purified HRP-C yields biocomposites with very high activity in acetate buffer that does not degrade the ZIF-8 structure. Using acetate instead of phosphate buffer can prevent the false high activity of HRP@ZIF-8 biocomposites caused by the degradation of ZIF-8 coating. At the same time, purification and especially oxidation of the carbohydrate component of enzymes prior to biomineralization lead to significantly improved activity of the biocomposites.

Automated summary

This article investigates the isoenzyme composition of commercial HRP and the influence of the carbohydrate component of the protein molecule on biomineralization. The findings suggest that purified HRP yields enzyme@ZIF-8 biocomposites with higher activity, while oxidation of the carbohydrate component of both commercial HRP and purified HRP-C produces biocomposites with very high activity in acetate buffer, without degradation of the ZIF-8 structure. Therefore, the impact of isoenzyme composition and carbohydrate component of the protein molecule should be considered when studying the biomineralization process.