Innovative Biocatalysts as Tools to Detect and Inactivate Nerve Agents

Abstract

Pesticides and warfare nerve agents are frequently organophosphates (OPs) or related compounds. Their acute toxicity highlighted more than ever the need to explore applicable strategies for the sensing, decontamination and/or detoxification of these compounds. Herein, we report the use of two different thermostable enzyme families capable to detect and inactivate OPs. In particular, mutants of carboxylesterase-2 from Alicyclobacillus acidocaldarius and of phosphotriesterase-like lactonases from Sulfolobus solfataricus and Sulfolobus acidocaldarius, have been selected and assembled in an optimized format for the development of an electrochemical biosensor and a decontamination formulation, respectively. The features of the developed tools have been tested in an ad-hoc fabricated chamber, to mimic an alarming situation of exposure to a nerve agent. Choosing ethyl-paraoxon as nerve agent simulant, a limit of detection (LOD) of 0.4 nM, after 5 s of exposure time was obtained. Furthermore, an optimized enzymatic formulation was used for a fast and efficient environmental detoxification (>99%) of the nebulized nerve agent simulants in the air and on surfaces. Crucial, large-scale experiments have been possible thanks to production of grams amounts of pure (>90%) enzymes.

Point-of-Care Diagnostics of COVID-19: From Current Work to Future Perspectives

“…Nowadays, biosensors are already of common use, such as electrochemistry-based glucometers for glucose determination in blood [108,109] or lateral-flow-based devices for fertility and pregnancy tests [110,111]. Other biosensors have been proposed for several applications in healthcare, such as wearable biosensors for healthcare monitoring [112] for the detection of toxic substances in human fluids [113] or in foods [114], including possible real-time detection in the environment [115][116][117][118]. The simpler its use, the more a biosensor can be introduced into daily life with user-friendly self-explanatory interfaces.…”

Structural and Functional Characterization of New SsoPox Variant Points to the Dimer Interface as a Driver for the Increase in Promiscuous Paraoxonase Activity

“…We previously demonstrated the ability of SsoPox, W263F and SacPox to hydrolyze a deadly nerve agent, cyclosarin [19]. In addition, we have recently reported the detoxification of other chemical warfare nerve agents including tabun, sarin, soman and cyclosarin using 3Mut [33]. It is of great interest to test the ability of 4Mut to hydrolyze these nerve agents.…”

Microbial Phosphotriesterase: Structure, Function, and Biotechnological Applications

“…The PTE biosensor is reported to have high reusability (0.3% per time sensed), achieving up to 90% stability in 1000 s and 70% longevity and selectivity (with the detection of six similar nerve agents) [41]. The development of this biosensor is based on the mechanism of hydrolysis of PTE in the OP compound [19,49,50]. Products from the hydrolysis process will change the pH and electrical charge, proton transfer to Asp 301 will occur [11,17,42].…”

“…Immobilization supports such as graphene, chitosan, sulphate chitosan, bovine serum, and glutaraldehyde have been used to stabilize and enhance the enzyme properties [41,50,51]. Currently, a novel microelectronic device based on a CMOS-compatible ISFET chip and PTE enzyme, combined with a microfluidic system has been developed by Pozio and his coworkers to detect OP compounds [43,49].…”

“…The current issue at hand is how to deliver the enzyme into our body and at the same time protect the enzyme from our own immune system. A number of experiments have been done using erythrocytes and liposomes as carriers for PTE inside mice [3,49]. However, the enzyme remained active for only 45 h at the most [8,14].…”