The and structural functions (Zheng et al. 2013). A

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., which catalyzes the hydrolysisof many organophosphorus compounds and highly reduces the toxicity of organophosphatepesticide and it can completely mineralize the organophosphate componds.

The OPH enzyme was coded by opd gene, were foundin two soil microorganisms namely Pseudomonas diminuta MG and Flavobacteriumsp. (Sethunathan et al. 1998). AlthoughOPH hydrolyzes a wide range of organophosphate componds, the effectiveness ofhydrolysis varies dramatically for differnt componds. Widely usedorganophosphorus insecticides like methyl parathion, chlorpyrifos, and diazinonare hydrolyzed slowly than 30 to 1,000 times is the preferred substrate,paraoxon (Cho et al.

2002). The catalytic rate is reduced due to theunfavorable interaction of these substrates with the active sites involved incatalysis and structural functions (Zhenget al. 2013).

A number of enzymes are capable of hydrolysing anumber of organophosphate triesters into less or non-toxic compounds. Theseenzymes are possible bioremediators because of their ability to decontaminateOP-containing waters and soils (Zheng et al. 2013). The most thoroughlycharacterized phosphotriesterases have been isolated from Flavobacterium sp.ATCC 27551, Pseudomonas diminuta (OPH) and Agrobacterium radiobacter (OpdA)(Fernanda et al.

2010). These enzymes belongto the binuclear metallohydrolase family and share high sequence andstructural homology. Phosphotriesterases are highly promiscuous enzymes,hydrolysing a large range of substrates. The phosphotriester hydrolysis by OPHhas 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.