Abstract

Recombinant bacterial cocaine esterase (CocE) represents a potential protein therapeutic for cocaine use disorder treatment. Unfortunately, the native enzyme was highly unstable and the corresponding mutagenized derivatives, RBP-8000 and E196-301, although improving in vitro thermo-stability and in vivo half-life, were a partial solution to the problem. For cocaine use disorder treatment, an efficient cocaine-metabolizing enzyme with a longer residence time in circulation would be needed. We investigated in vitro the possibility of developing red blood cells (RBCs) loaded with RBP-8000 and E196-301 as a biocompatible system to metabolize cocaine for a longer period of time. RBP 8000 stability within human RBCs is limited (approximately 50% residual activity after 1 h at 37°C) and not different as for the free enzyme, while both free and encapsulated E196-301 showed a greater thermo-stability. By reducing cellular glutathione content during the loading procedure, in order to preserve the disulfide bonds opportunely created to stabilize the enzyme dimer structure, it was possible to produce an encapsulated protein maintaining 100% stability at least after 4 h at 37°C. Moreover, E196-301-loaded RBCs were efficiently able to degrade cocaine in a time- and concentration-dependent manner. The same stability results were obtained when murine RBCs were used paving the way to preclinical investigations. Thus, our in vitro data show that E196-301-loaded RBCs could act as efficient bioreactors in degrading cocaine to non-toxic metabolites to be possibly considered in substance-use disorder treatments. This approach should now be investigated in a preclinical model of cocaine use disorder to evaluate if further protein modifications are needed to further improve long term enzyme stability.

Document Type

Article

Publication Date

9-10-2020

Notes/Citation Information

Published in Frontiers in Physiology, v. 11, article no.: 573492.

© 2020 Rossi, Pierigè, Agostini, Bigini, Termopoli, Cai, Zheng, Zhan, Landry and Magnani.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

Digital Object Identifier (DOI)

https://doi.org/10.3389/fphys.2020.573492

Funding Information

This work was partially supported by EryDel S.p.A. The authors declared that this study received funding from EryDel S.p.A.

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