Glucose Oxidase Initiates Radical Polymerizations by Direct Electron Transfer to Monomers

TL;DR

Glucose oxidase can start polymer reactions by transferring electrons to monomers, enabling polymer synthesis under mild conditions without needing light or initiators.

Contribution

GOx initiates radical polymerizations via direct electron transfer to monomers, a previously unknown activity.

Findings

GOx initiates polymerization of acrylamides and methacrylates without initiators or light.

Monomers orient specifically in GOx's active site, as revealed by computational docking.

A fluorescence assay was developed to screen GOx's polymerization activity in 96-well plates.

Abstract

Glucose oxidase (GOx)
is a widely used and studied enzyme,
yet
it continues to surprise with previously unknown activities. We report
GOx to initiate radical polymerizations of acrylamides and methacrylates
without the need for initiators or irradiation by light, simply by
carrying out the polymerizations in the absence of oxygen at high
glucose concentrations. The enzyme oxidizes glucose and concomitantly
transfers an electron and a proton to a monomer, thereby creating
a radical species that starts the polymerization. Computational docking
studies revealed specific orientations of monomers in the enzyme’s
active site. GOx’s ability to deoxygenate solutions was combined
with its initiation activity to achieve polymerizations in nondeoxygenated
conditions, allowing polymerizations in a 96-well plate format, and
a fluorescence assay was developed to screen the enzyme’s polymerization
activity. GOx’s polymerization activity opens the route to
polymer synthesis under mild and biological relevant conditions and
allows integration of GOx-catalyzed radical polymerizations into biosensors
as well as living and synthetic cells.

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