Laccases represent a class of enzymes with various industrial and biotechnological applications due to their ability to oxidize lignin compounds and persistent environmental pollutants.[1] As their applications require the ability of the laccase to maintain activity in aggressive environmental conditions (presence of various degrading agents), its protection is mandatory. In order to protect the enzyme, and increase its stability in aggressive environment, we propose a new approach: enzyme encapsulation in polymer vesicles (polymersomes) with oxygen permeable membrane [2]. In situ active laccase (Lac) serves as active component for the design of laccase-based nanoreactors with improved efficiency due to the protective role of polymersomes. Inside polymersomes Lac is simultaneously protected and accessible for its key substrate, oxygen (Figure 1A). Laccase nanoreactors act as a source of reactive oxygen species (ROS) because ROS produced in situ escape the nanoreactor, and react with the corresponding compounds present in the environment of polymersomes. We synthesized poly(N-vinylpyrrolidone)-poly(dimethylsiloxane) (PDMS-PNVP) copolymers for generation of polymersomes due to the high permeability of membrane for oxygen and ROS. Five different PDMS-PNVP polymers were synthesized in order to determine those that are able to self-assemble into polymersomes with the intended permeability and size distribution. The successful Lac encapsulation inside the PDMS-PNVP polymersomes, and its in situ activity were tested by a combination of spectrophotometric methods using ABTS as substrate (Figure 1B)Figure 1. (A) Spin trapping of ROS species formed in a 5mg/mL laccase solution in phosphate saline solution at pH 4.25; (B) Laccase activity assay in nanoreactors and in free conditions.Refrences : 1. R. Bourbonnais et al;  Appl. Environ. Microbiol. 1997 , 63, 4627.2.M. Spulber et al.,J. Am. Chem. Soc.. 2013 , 135,  9204.

ROS permeable polymersomes for laccase nanoreactors

247th National Meeting (2014)

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