(676d) Fabricating Multi-Enzyme Catalyst in Reverse Emulsions

This presentation describes our continuous efforts towards fabricating multi-enzyme catalysts. As described elsewhere^[1], the first step is to encapsulate enzyme in aldehyde-functionalized Pluronic (PCHO) micelles, followed by forming the Schiff-base bonds between amine groups of proteins and aldehyde groups of the Pluronic polymers. This thus encapsulates protein into the interior region of the micelles. The versatility of this method was validated using various enzyme samples including glucose oxidase (GOx), horseradish peroxidase (HRP), Candida antarctica lipase B (CALB) and cytochrome c (Cyt c). In all cases, the encapsulation of enzyme was above 90%.

We then moved onto the fabrication of multi-enzyme micelle, using GOx and HRP as example. A proximity effect was observed, facilitating the intermediate consumption, as compared to both the individually encapsulated enzymes and their native counterparts in free solution. The proximity effect was further confirmed using catalase (CAT) to compete with the GOx–HRP microgel, in which inviable H₂O₂ was obtained by CAT, indicating that H₂O₂ produced by GOx was uptaken by HRP instead of entering the bulk solution. The GOx-HRP microgel remained 95% of the initial activity after 10 cycles. The circumvention of chemical modification of the enzyme simplifies the process, while the encapsulation yield may be further enhanced by molecular engineering of the phase forming polymer, making this method promising for multiple enzyme catalysis, particularly those in non-aqueous phase.

[1] Xiaoling Wu, Jun Ge,* Jingying Zhu, Yifei Zhang, You Yong and Zheng Liu*, Chem. Commun.,2015, 51, 9674