Reversible Deactivation of Enzymes by Redox‐Responsive Nanogel Carriers

Abstract

Novel redox-responsive polymeric nanogels that allow highly efficient enzyme encapsulation and reversible modulation of enzyme activity are developed. The nanogel synthesis and encapsulation of enzyme are performed simultaneously via in situ crosslinking of pyridyldisulfide-functionalized water-soluble reactive copolymers, which are synthesized via reversible addition-fragmentation chain transfer copolymerization. Obtained nanogels with loaded cellulase demonstrate very good colloidal stability in aqueous solutions. The enzymatic activity of cellulase is greatly reduced when encapsulated in the nanogels and rapidly recovered in 10 × 10 m dithiothreitol solution. Fluorescence resonance energy transfer (FRET)-based experiments indicate that the recovered enzymatic activity is mainly ascribed to the release of the enzyme due to the degradation of the disulfide crosslinking network after addition of dithiothreitol (DTT), instead of the enhanced substrate transport rate. The developed enzyme immobilization method opens new possibilities for reversible activation/deactivation of enzymes and opens up new directions for targeted protein therapy and biotechnology applications.

Thiol-Mediated Chemoselective Strategies for In Situ Formation of Hydrogels

“…A modified version of thiol-disulfide exchange between thiols and activated disulfides (e.g., pyridyl disulfide) proceeds faster than thiol oxidation to form disulfides, and has been applied to polymer crosslinking to form nanogels within hours [41]. Recent examples include the work by Peng et al that demonstrated the crosslinking of pyridyl disulfide-presenting copolymers with four-armed, thiol-terminated linkers [42]. The disulfide-crosslinked nanogels were used for the encapsulation and deactivation of a cellulase.…”

“…Crosslinking of pyridyl disulfide-presenting polymer self-assembly with thiol-terminated linkers for the encapsulation and deactivation of a cellulase. Image modified with permission from [42]. Copyright 2016 Wiley.…”

Double‐crosslinked reversible redox‐responsive hydrogels based on disulfide–thiol interchange

“…It is well‐known that disulfide bonds can be simply cleaved and reformed in the presence of reducing agents and oxidants under mild conditions, respectively . As a consequence of this reversible reaction, disulfide crosslinked polymer gels have attracted increased attention and been widely reported for numbers of applications, such as drug release and enzyme immobilization . N , N ‐bis(acryloyl cystamine) (BAC), a disulfide‐contained crosslinker, has been extensively employed to endow reversibility or partial/complete degradation in hydrogels for PNiPAAm and polyacrylamide (PAAm) .…”

“…[33][34][35] As a consequence of this reversible reaction, disulfide crosslinked polymer gels have attracted increased attention and been widely reported for numbers of applications, such as drug release and enzyme immobilization. [36][37][38][39][40][41] N,N-bis(acryloyl cystamine) (BAC), a disulfide-contained crosslinker, has been extensively employed to endow reversibility or partial/complete degradation in hydrogels for PNiPAAm and polyacrylamide (PAAm). [42][43][44] Moreover, combining with commonly used crosslinker N,N-methylenebis(acrylamide) (BIS), a partially degradable and reversible hydrogel system can be achieved.…”

Comparison of Candida antarctica Lipase B Variants for Conversion of ε-Caprolactone in Aqueous Medium—Part 2

“…Investigations of alternative carriers such as nano- or microgels for immobilization of catalysts in general and enzymes in particular attracted more and more interest during the last years [23,24]. Hereby, the influence of the gel network on the enzymatic activity and the protection against solvents are important research issues among others [25,26,27]. Recently, we reported about the synthesis and immobilization of CaLB in tailormade microgels and showed the influence of the microgel polarity on the ring-opening polymerization activity of CaLB [28,29,30].…”