Laccase Activation in Deep Eutectic Solvents

abstract

The research on alternative solvents and cosolvents is relevant when envisioning the improvement of biocatalytic reactions. Among these solvents and cosolvents, deep eutectic solvents (DES) may be considered as customizable new reaction media for biocatalysis. Accordingly, in this work, 16 DES aqueous solutions, as well as the individual DES components at the same conditions, have been investigated in laccase-catalyzed reactions. Cholinium- and betaine-based DES formed with polyols at different molar ratios and concentrations were evaluated. The results reported show that in the presence of most DES the laccase activity is preserved and, with a particular DES, enhanced up to 200%. Molecular docking studies demonstrated that while most DES components establish hydrogen bonds with the enzyme amino acids, those that establish stronger interactions with the enzyme (expressed by absolute values of docking affinity energies) lead to an enhanced laccase activity. Finally, the laccase stability was evaluated in additional tests under extreme storage temperatures (60 degrees C and -80 degrees C). Although no significant protection to high temperatures was afforded by DES, an enhanced laccase activity when stored at low temperatures was found, at least up to 20 days. Combining experimental results and molecular docking, this work shows that DES can be designed as cosolvents to improve biocatalytic reactions.

keywords

CRYSTAL-STRUCTURE; IONIC LIQUIDS; STABILITY; NANOSTRUCTURE; BIOCATALYSIS; OXIDATION; BETAINE; WATER

subject category

Chemistry; Science & Technology - Other Topics; Engineering

authors

Toledo, ML; Pereira, MM; Freire, MG; Silva, JPA; Coutinho, JAP; Tavares, APM

Groups

G4 - Renewable Materials and Circular Economy
G5 - Biomimetic, Biological and Living Materials
G6 - Virtual Materials and Artificial Intelligence

Projects

CICECO - Aveiro Institute of Materials (UID/CTM/50011/2019)

Desenvolvimento de nanomateriais sustentáveis para a purificação de fármacos anti-leucémicos (NanoPurAsp)

Projeto de Investigação Exploratória: Ana Paula Tavares (IF Ana Paula Tavares)

acknowledgements

This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, FCT ref. UID/CTM/50011/2019, financed by national funds through the FCT/MCTES and within the Project POCI-01-0145-FEDER-031268 - funded by FEDER, through COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao (POCI), and by national funds (OE), through FCT/MCTES. M.L.T. acknowledges University of Sao Paulo (Mobilidade internacional de duracao especial). A.P M.T. acknowledges FCT for the Investigator Programme (IF/01634/2015). M.M.P. acknowledges the Ph.D. grant (2740-13-3) and financial support from Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior - Capes. J.P.A.S. acknowledges the support of FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-Process Number 2016/06683-0). This article was presented at the 13th International Chemical and Biological Engineering Conference (CHEMPOR 2018). The authors acknowledge the Scientific and Organizing Committees of the Conference for the opportunity to present this work.