EC Number   |
Reaction |
Reference |
|---|
   3.1.8.2 | diisopropyl fluorophosphate + H2O = diisopropyl phosphate + fluoride |
analysis of the catalytic reaction mechanism of the enzyme. Proposed mechanism for phosphoenzyme intermediate formation involving Asp229 as the nucleophile. (i) Asp229 attacks the phosphorus center of DFP to form a pentavalent intermediate and (ii) the P-F bond dissociates to form a tetrahedral phosphoenzyme intermediate. Hydrolysis of the phosphoenzyme intermediate is not shown. And proposed mechanism for hydrolysis involving an activated water as the nucleophile. (i) Asp229 abstracts a proton from a water molecule either stepwise or in concert as (ii) water attacks the phosphorus center, (iii) Glu21 abstracts a proton either stepwise or in concert as water forms a bond with phosphorus, and (iv) the P-F bond dissociates |
750923 |
| 3.1.8.2 | diisopropyl fluorophosphate + H2O = diisopropyl phosphate + fluoride |
calcium coordinating residue D229, in concert with direct substrate activation by the metal ion, renders the phosphorus atom of the substrate susceptible for attack of water, through generation of a phosphoenzyme intermediate |
680347 |
| 3.1.8.2 | diisopropyl fluorophosphate + H2O = diisopropyl phosphate + fluoride |
catalytic mechanism, H287 is required for catalytic activity |
646562 |
| 3.1.8.2 | diisopropyl fluorophosphate + H2O = diisopropyl phosphate + fluoride |
catalytic reaction mechanism involving residue Asp269, molecular dynamics and modelling, overview |
751626 |
| 3.1.8.2 | diisopropyl fluorophosphate + H2O = diisopropyl phosphate + fluoride |
enzyme exhibits stereoselectivity toward the chiral phosphorus center of the p-nitrophenyl analogs of sarin and soman |
646560 |
| 3.1.8.2 | diisopropyl fluorophosphate + H2O = diisopropyl phosphate + fluoride |
molecular details of the catalytic mechanism of h-PON1 |
749628 |
| 3.1.8.2 | diisopropyl fluorophosphate + H2O = diisopropyl phosphate + fluoride |
squide-type enzyme: diisopropyl fluorophosphate hydrolysed more rapidly than soman, Mazur-type enzyme: soman hydrolysed more rapidly than diisopropyl fluorophosphate |
646551, 646564 |
| 3.1.8.2 | diisopropyl fluorophosphate + H2O = diisopropyl phosphate + fluoride |
the catalytic mechanism of DFPase is investigated using the hybrid density functional theory method B3LYP with a large quantum chemical model of the active site abstracted from the X-ray crystal structure. For the first step, two different pathways are considered: (1) residue Asp229 as a nucleophile inline attacks on the phosphorus center and (2) an activated water molecule as the nucleophile attacks on the phosphorus center. Both the Asp229 and the activated water molecule are capable of proceeding nucleophilic attack on the substrate in the presence of Ca2+ ion with the associated barriers 14.8 and 6.0 kcal/mol, respectively. The latter is much easier to perform the nucleophile attack. From the phosphoenzyme intermediate with the hexa-coordinated Ca2+, the uncoordinated Glu21 functions as a general base activated an additional water molecule to attack the carbon center of Asp229 and make the phosphate release. Residues Asn120 and Asn175 promote the elimination of the fluoride via donating strong hydrogen bonds. Residue Asp229 plays a dual role during the hydrolysis reaction process, either as a nucleophile or as a general base to activate the water nucleophile. The role of the calcium ion is providing a necessary conformation of the active site, facilitating the nucleophile formation and substrate orientation |
752291, 755573 |
| 3.1.8.2 | diisopropyl fluorophosphate + H2O = diisopropyl phosphate + fluoride |
the enzyme exhibits stereoselectivity toward the hydrolysis of chiral substrates with a preference for the S-P enantiomers |
646563 |
