IUBMB Enzyme Nomenclature


Accepted name: aryldialkylphosphatase

Reaction: An aryl dialkyl phosphate + H2O = dialkyl phosphate + an aryl alcohol

Other name(s): organophosphate hydrolase; paraoxonase; A-esterase; aryltriphosphatase; organophosphate esterase; esterase B1; esterase E4; paraoxon esterase; pirimiphos-methyloxon esterase; OPA anhydrase (ambiguous); organophosphorus hydrolase; phosphotriesterase; paraoxon hydrolase; OPH; organophosphorus acid anhydrase

Systematic name: aryltriphosphate dialkylphosphohydrolase

Comments: Acts on organophosphorus compounds (such as paraoxon) including esters of phosphonic and phosphinic acids. Inhibited by chelating agents; requires divalent cations for activity. Previously regarded as identical with EC arylesterase.

Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 117698-12-1


1. Aldridge, W.N. Serum esterases. I. Two types of esterase (A and B) hydrolysing p-nitrophenyl acetate, propionate and butyrate and a method for their determination.Biochem. J. 53 (1953) 110-117.

2. Bosmann, H.B. Membrane marker enzymes. Characterization of an arylesterase of guinea pig cerebral cortex utilizing p-nitrophenyl acetate as substrate. Biochim. Biophys. Acta 276 (1972) 180-191. [PMID: 5047702]

3. Mackness, M.I., Thompson, H.M., Hardy, A.R. and Walker, C.H. Distinction between 'A'-esterases and arylesterases. Implications for esterase classification. Biochem. J. 245 (1987) 293-296. [PMID: 2822017]

4. Main, A.R. The differentiation of the A-type esterases in sheep serum. Biochem. J. 75 (1960) 188-195.

5. Reiner, E., Aldridge, W.N. and Hoskin, C.G. (Eds.) Enzymes Hydrolysing Organophosphorus Compounds, Ellis Horwood Ltd., Chichester, UK, 1989.

[EC created 1989]

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