posted on 2022-01-14, 23:13authored byMeghna Thakur, Scott N. Dean, Martin Moore, Joseph R. Spangler, Brandy J. Johnson, Igor L. Medintz, Scott A. Walper
Enzymatic decontamination of organophosphate
compounds offers a
biofriendly pathway to the neutralization of highly dangerous compounds.
Environmental dissemination of enzymes, however, is an ongoing problem
considering the costly process of production and chemical modification
for stability that can diminish catalytic activity. As a result, there
is interest in the potential for enzymatic encapsulation in situ or
into nascent bacterial membrane vesicles to improve catalytic stability
across various environmental challenges associated with storage and
field deployment. In this study, we have engineered bacterial outer
membrane vesicles (OMVs) to encapsulate the diisopropyl fluorophosphatase
(DFPase), an enzyme originally isolated from squid Loligo
vulgaris and capable of hydrolyzing diisopropyl fluorophosphate
(DFP) and other organophosphates compounds. Here we employed a recombinant
lipopeptide anchor to direct recruitment of DFPase into OMVs, which
were isolated from culture media and tested for catalytic activity
against both diisopropyl fluorophosphate and paraoxon. Our encapsulation
strategy prevented the loss of catalytic activity despite lyophilization,
extended storage time (2 days), and extreme temperatures up to 80
°C. These data underscore the appeal of DFPase as a biodecontaminant
of organophosphates as well as the potential for OMV packaging in
stabilized field deployment applications.