Bacterial detoxification of diisopropyl fluorophosphate

Augmented hydrolysis of diisopropyl fluorophosphate in engineered mutants of phosphotriesterase.

The phosphotriesterase from Pseudomonas diminuta hydrolyzes a wide variety of organophosphate insecticides and acetylcholinesterase inhibitors. The rate of hydrolysis depends on the substrate and can range from 6000 s-1 for paraoxon to 0.03 s-1 for the slower substrates such as diethylphenylphosphate. Increases in the reactivity of phosphotriesterase toward the slower substrates were attempted ...

The inhibition of purified, human plasma cholinesterase with diisopropyl fluorophosphate.

Previous communications from this Laboratory have shown that the inhibition of cy-chymotrypsin by diisopropyl fluorophosphate (DFP) is a stoichiometric reaction that comprises the introduction of a single diisopropyl phosphate group into the molecule of cu-chymotrypsin, the elimination of fluorine as HF, and the production of an undenatured, crystallizable, inhibited enzyme protein (l-3). Sever...

Radioactive diisopropyl fluorophosphate as a platelet label: an evaluation of in vitro and in vivo technics.

Mode of inhibition of chymotrypsin by diisopropyl fluorophosphate; introduction of phosphorus.

It has been previously shown that the esterase and proteinase activities of trypsin and chymotrypsin (1, 2) were equally inhibited by diisopropyl fluorophosphate (DFP) (3). With chymotrypsin, 50 per cent inhibition occurred when 0.55 mole of inhibitor per mole of enzyme1 was used at pH 7.7. On the basis of a linear relationship between the-per cent inhibition and the concentration of DFP, 1.1 m...

The Mechanism of in Vitro and in Vivo Inhibition of Cholinesterase Activity by Diisopropyl Fluorophosphate

cholinergic effects of the fluorophosphates and those of physostigmine was noted by the British workers, McCombie et al.,’ and by Adrian and his group.2 The theory of chemical mediation of the transmission of nerve impulses through the autonomic nervous system identifies ac&ylcholine as the mediator. The presence of the enzyme, cholinesterase, at sites where acetylcholine is liberated by the ne...