• 한국군사과학기술학회지
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• 제4권1호
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• pp.188-197
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• 2001

Organophosphorus acid anhydrolases(OPAA) catalyzing the hydrolysis of toxic organophosphates have been found in a variety of prokaryotic and eukaryotic organisms. Of the several kinds of OPAA that can degrade nerve agents, such as DFP, sarin and soman, a OPAA gene harbored in the chromosomal DNA of Alteromonas haloplanktis strain was subcloned in order to develope an enzymatic degradation method of toxic organophosphorus compounds. For this 1481 bp DNA fragment containing OPAA gene and its flanking regions has been synthesized through PCR using chromosomal DNA of A. haloplanktis strain. After subcloning and subsequent expression, crude OPA anhydrolase was prepared and assayed. It was shown that the OPAA had a very high hydrolytic activity on DFP. The specific activity of the enzyme was 1,110 $\mu$mole.$min^{p-1}.mg^{-1}$ protein. It seemed that OPAA with such a high hydrolytic activity may give a good prospects to its use, as a biodegradation tool, in detoxifying toxic organophosphorus compounds, such as pesticides and chemical stockpiles which are posing a potential threat to the field environment and human health.

• BMB Reports
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• 제34권5호
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• pp.440-445
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• 2001

Pesticide waste and chemical stockpiles are posing a potential threat to both Vie environment and human health. There is currently a great effort toward developing effective and economical methods for the detoxification of these toxic organophosphates. In terms of safety and economy, enzymatic biodegradation has been recommended as the most promising tool to detoxify these toxic materials. To develop an enzymatic degradation method to detoxify such toxic organophosphorus compounds, a gene encoding organophosphorus acid anhydrolase (OPAA) from genomic DNA of Alteromonas haloplanktis C was subcloned and expressed. The enzyme consists of a single polypeptide chain with a molecular weight of 48 kDa. It demonstrates strong hydrolyzing activity on sarin, an acetylcholinesterase inhibitor. Moreover, its high activity is sustained for a considerable length of time. It is projected that the recombinant OPAA can be applied as an enzymatic tool that can be used not only for the detoxification of pesticide wastes, but also for the demilitarization of chemical stockpiles.

• 한국군사과학기술학회지
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• 제2권2호
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• pp.140-147
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• 1999

A gene expressing organophosphorus acid (OPA) anhydrolases have been cloned from Alteromonas haloplanktis strain and expressed in bacterial strain BL21. Crude extract was prepared from the transformed bacterial strain BL2l and used in testing its degrading capability of real nerve gas, soman and sarin. Within 1 minute after the start of the reaction, nearly 65% of the soman added to the reactant(3mM) was degraded by adding 1 mg of the crude extract enzyme(20.0 Unit $mg^-{1}$ crude protein). In 6 minutes, the reaction reached at its steady state, which indicates that soman was completely degraded by that time. In the case of sarin, the degradation efficiency was observed to be about 0.7 times of that of soman. If the specific activity of OPAA is enhanced by both increased expression efficiency and purification, OPAA seems to be applied for the development of decontaminant of skin, especially of eye.