Activity and Stability of Chloroperoxidase in the Presence of Small Quantities of Polysaccharides: A Catalytically Favorable Conformation Was Induced

Abstract

Chloroperoxidase (CPO) is thought to be the most versatile heme-containing enzyme with enormous applications in organic synthesis, biotransformation, pharmaceutical production, and detoxification of environmental pollutants. Any improvement in the stability of this enzyme will greatly enhance its application in the mentioned areas. In the present study, the effects of three polysaccharides (soluble starch, β-cyclodextrin, and dextrin) on the stability of CPO at elevated temperatures (20, 30, 35, 40, and 50 °C) or in aqueous-organic solvents media (methanol, dioxane, DMSO, and DMF) were investigated. An improved catalytic performance of CPO was observed in the presence of a small amount of the three polysaccharides, where dextrin provided the most effective promotion. The changes of enzyme structure and microenvironment around heme in the presence of additives were studied by fluorescence, circular dichroism, and UV-vis spectra analyses, as well as kinetic parameters measurement. A catalytically favorable structure of CPO was induced, including the strengthening of the α-helix structure and more exposure of heme for easy access of the substrate, resulting in an increase of catalytic turnover frequency (k (cat)) and the improvement of affinity and selectivity of CPO to substrate. The results revealed that the introduction of trace soluble starch, β-cyclodextrin, and dextrin (<10 μmol/L) in reaction media was an effective strategy for the enhancement of the thermodynamic and the operational stability of the enzyme, which are promising in view of the industrial applications of this versatile biological catalyst.

Specific oxyfunctionalisations catalysed by peroxygenases: opportunities, challenges and solutions

“…The same authors had previously reported similar beneficial effects by poly saccharides. 77,78 One of the major limitations of biocatalysis in general lies with the very poor water solubility of many (hydrophobic) reactants of interest. Unfortunately academic researchers tend to circumvent this limitation by adjusting the substrate loading of their reactions to the aqueous solubility of the reagents.…”

Catalytic Activity and Application of Immobilized Chloroperoxidase by Biometric Magnetic Nanoparticles

“…Chloroperoxidase (CPO; E.C. 1.11.1.10), which is a versatile heme-containing enzyme, could catalyze sulfoxidation, epoxidation, dismutation, halogenation, and oxidation of numerous compounds with extensive high regioselectivity and enantioselectivity. , Such excellent catalytic properties enable CPO to have a great potential application in the synthesis of drugs and intermediates, but the lack of long-term operational stability has impeded its feasibility for practical industrial use. , Therefore, it is necessary to develop an effective strategy for improving the stability of CPO. , Immobilization is the most commonly used way to improve the stability of enzyme in industry. Various materials, such as mesoporous silica, − organic polymer matrices, , graphene oxide (GO) nanosheets, and nanotubes, , have been selected as supports to facilitate the stability and recycling of immobilized CPO.…”

“…1,2 Such excellent catalytic properties enable CPO to have a great potential application in the synthesis of drugs and intermediates, but the lack of long-term operational stability has impeded its feasibility for practical industrial use. 3,4 Therefore, it is necessary to develop an effective strategy for improving the stability of CPO. 5,6 Immobilization is the most commonly used way to improve the stability of enzyme in industry.…”