Organophosphate hydrolases

A.K. Singh, A.W. Flounders, J.V. Volponi, C.S. Ashley, K. Wally, and J.S. Schoeniger, Development of sensors for direct detection of organophosphates. Part I immobilization, characterization and stabilization of acetylcholinesterase and organophosphate hydrolase on silica supports. Biosens. Bioelectron. 14, 703-713 (1999). 

D. Josse, P. Masson, Human Plasma Paraoxonase (HuPONl) An Anti-Atherogenic Enzyme with Organophosphate Hydrolase Activity , Ann. Pharm. Fr. 2001, 59, 108-118. 

The inactivation and detoxification of paraoxon and congeners are catalyzed by the so-called A-esterases, which, as discussed, comprise aryleste-rase (sometimes still called paraoxonase, EC 3.1.1.2) and phosphoric triester hydrolases (phosphotriesterases, EC 3.1.8) subdivided into aryldialkylphos-phatase (organophosphate hydrolase, paraoxonase, EC 3.1.8.1) and organophosphorus acid anhydrolases (EC 3.1.8.2 see Sect. 9.3.7) [65][69][106-108], These activities, which occur mostly in the mammalian liver and... 

FIGURE 8.2 Effect of organophosphate hydrolase on methyl parathion degradation. 

Efremenko, E.N., and Sergeeva, V.S. (2001) Organophosphate hydrolase - an enzyme eatalyzing degradation of phosphorous-containing toxins and pesticides, Russian Chem. Bui. (Int. Ed.) 50 1826-1832. 

Efremenko, E.N., Votchitseva, Yu.V., Aliev, T.K., and Varfolomeyev, S.D. (2005) Recombinant plasmid DNA pTES-His-OPH encoding synthesis of polypeptide with properties of organophosphate hydrolase, and strain E.coli - producer of polypeptide with properties of organophosphate hydrolase. Patent RU 2255975. 

Efremenko, E., Votchitseva, Yu., Plieva, F., Galaev, T, and Mattiasson, B. (2006) Purifieation of Hisg-organophosphate hydrolase using monolithic supermacroporous polyacrylamide cryogels developed for immobilized metal affinity chromatography, Appl. Microbiol. Biot. 70(5) 558-563. 

Acetylcholinesterase, butyrylcholmesterase, paraoxonase, organo-phosphonic acid anhydrolase, organophosphate hydrolase... 

Crystal structure of the G117H mutant of human butyrylcholinesterase, a designed organophosphate hydrolase. 

Schopfer, L.M., Ticu-Boeck, A., Broomfield, C.A., Lockridge, O. (2004). Mutants of human hutyrylcholinesterase with organophosphate hydrolase activity evidence that Hisl 17 is a general base catalyst for hydrolysis of echothiophate. J. Med. Chem. Def 2 1-21. 

Pseudomonas diminuta (organophosphate hydrolase) immobilized on nylon performed for weeks without leaching (Caldwell and Raushel, 1991a, b). The type of support material was a key factor in the successful degradation or organophosphates (Havens and Rase, 1991). 

As described above (see Section VILA), soluble ChE and oxime together detoxify OP compounds. These features were combined to developed a sponge product composed of ChE (FBS-AChE and EqBChE), organophosphate hydrolase (rabbit or bacterial OPH), oxime (2-PAM or HI-6), and polyurethane foam combinations for the removal and decontamination of OP compounds from medically important biological surfaces such as skin. This is an important extension of the bioscavenger approach to external decontamination and protection against organophosphate toxicity, since currently... 

During the last few years an alternative approach for organophosphates detection has been proposed (40, 41). It relays on the monitoring of the reaction of enzymatic hydrolysis of OPCs by a specific microbial enzyme, organophosphate hydrolase (OPH). OPH-based biosensors have been shown to be useful for direct detection of various OPCs (40-43), as well as for discrimination between different classes of... 

OPH has broad organophosphate hydrolase activity and is able to cleave various phosphorus-ester bonds (P-0, P-CN, P-F, P-S) (Schoheld and DiNovo 2010). Another very similar enzyme has been identified in the soil bacterium. Agrobacterium radiobacter (OpdA). Like the OPH, OpdA displays extraordinary catalytic efficiency for OPs for instance, the kcaJK of OpdA for the pesticide methyl paralhion is in the order of 3 x 10 s M (Scott et al. 2008 Bigley and Ranshel 2013). 

Researchers have found bacterial species, such as Pseudomonas diminuta, Flavobacterium sp. and A. coli, possessing the organophosphate hydrolase enzymes playing an important role in OPs degradation, since the enzymatic hydrolysis rates are 40-2450 times faster than chemical hydrolysis by 0.1 N NaOH at 40 C and the activity of these enzyme are stable at temperatures up to 45-50 °C (Malghani et al. 2009 Richins et al. 1997). 

Lu, H. D., Wheeldon, 1. R., and Banta, S. 2010. Catalytic biomaterials Engineering organophosphate hydrolase to form seU-assembUng enzymatic hydrogels. Protein Eng Des Sel, 23 559-66. 

Trovaslet-leroy, M., Musilova, L., Renault, E, et al., 2011. Organophosphate hydrolases as catalytic bioscavengers of organophosphorus nerve agents. Toxicol. Lett. 206,14-23. 

Monitoring the amount of pesticides in water and soil is an effective way to detect the abuse of pesticides in agriculture. Because pesticides can inhibit the activity of many enzymes, such as acetylcholinesterase (AChE), butyrylcholi-nesterase (BCliE), organophosphate hydrolase (OPH), and tyrosinase (Tyr), various inhibition biosensor systems emerged in recent years as promising alternatives for in situ detection of pesticides. Modem methods for the detection of pesticides usually involve liquid or gas chromatography coupled to mass spectrometric detection (HPLC-MS, GC-MS), requiring an appropriate sample preparation (as seen in Table 8.1). However, optical and electrochemical detection methods were also developed for this purpose. 

Pedrosa VA, Paliwal S, Balasubramanian S, Nepal D, Davis V, Wild J, Ramanculov E, Simonian A (2010) Enhanced stability of enzyme organophosphate hydrolase interfaced on the carbon nanotubes. Colloids Surf B 77(l) 69-74. doi 10.1016/j.colsurfb.2010.01.009... 

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