The pesticides have facilitated the development andalso expansion of agriculture in world wide. Organophosphate belong to a classof highly toxic neurotoxins that are commonly used as pesticides and chemicalwarfare agent (Surekha Rani et al. 2008).The continuous use of organophosphate in intensive quantity throughout theworld and their potential neurotoxicity to humans has wind to the developmentof various efficient and safety scheme of bioremediation to plenty with theirwide dispersal in the ecosystem (Cho et al. 2002). Enzymatic degradation byorganophosphorus hydrolase (OPH) has received considerable attention.
Thisattention provides the possibility of both eco friendly and in situdetoxification (Catherine et al. 2002). The focussing of this study isorganophosphorus hydrolase (OPH, E.
C. 220.127.116.11), which catalyzes the hydrolysisof many organophosphorus compounds and highly reduces the toxicity of organophosphatepesticide and it can completely mineralize the organophosphate compounds.
The OPH enzyme was coded by opd gene, were foundin two soil microorganisms namely Pseudomonas diminuta MG and Flavobacteriumsp. (Sethunathan et al. 1998). OPH hydrolyzes a wide range oforganophosphate compounds and the effectiveness of hydrolysis variesdramatically for differnt compounds like widely used organophosphorusinsecticides methyl parathion, chlorpyrifos, and diazinon are hydrolyzed slowlerthan paraoxon (Cho et al.
2002). The catalytic rate is reduced due to the unfavorableinteraction of the substrates with the active sites involved in catalysis and alsostructural functions (Zheng et al. 2013).A number of enzymes can able to hydrolysis a numberof organophosphate trimesters compound into less or non-toxic compound.
OPH havingthe ability to hydrolyzing the P–S bond of phosphonothioate esters. This enzymeis a possible bioremediator because of their ability to decontaminateOP-containing waters and soils (Zheng et al. 2013). The phosphotriesterases isolatedfrom Flavobacterium sp. ATCC 27551, Pseudomonas diminuta (OPH)and Agrobacterium radiobacter (OpdA) was thoroughly characterized as abioremidiator (Fernanda et al. 2010). These enzymes belong to the binuclear metallohydrolasefamily and share high sequence and structural homology.
Phosphotriesterases arehighly promiscuous enzymes, hydrolysing a large range of substrates. Thephosphotriester hydrolysis by OPH has been studied extensively (Castro et al. 2016).In a proposed reaction scheme, based on largely crystal structures with boundinhibitors, the phosphoryl oxygen of the substrate binds to the ?-metalion (Janet et al.2005; Laothanachareo et al. 2008).In the present research focuses on the interactionand degradation of chlorpyrifos by OPH enzyme, as this is responsible fordetoxification. The molecular docking study was conducted under FlexX dockingsoftware package.