From Enzyme Encapsulation to Environmental Solutions: Photostable Laccase in DOPC Vesicles

Abstract

The laccase enzyme offers significant advantages for the removal of organic contaminants; but its stability and effectiveness in bioremediation can be compromised by photo-induced degradation processes. To address this challenge, we investigated the immobilization of laccase in unilamellar and multilamellar vesicles of dioleoyl phosphatidylcholine (DOPC) as a means to enhance its photo-stability while preserving its catalytic activity. Enzymatic activity was evaluated spectroscopically for both free and encapsulated laccase, before and after UVB irradiation. Our results demonstrate that DOPC vesicles effectively encapsulate the laccase enzyme, maintaining its activity within the vesicles. Moreover, the substrate syringaldazine, a model compound for laccase activity studies, was able to permeate through the bilayer. Notably, encapsulated laccase exhibited significantly higher retention of enzymatic activity (REA) post-irradiation compared to the free enzyme. In conclusion, both unilamellar and multilamellar vesicles provide substantial photoprotection for laccase against UVB light. This protective effect is attributed to the enzyme's confinement within a system that scatters high-energy photons. Furthermore, the simplicity and ease of large-scale production of multilamellar vesicles present an advantageous option for various applications, including bioremediation.