|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 18.104.22.168
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
Most BioCyc compounds have been protonated to a reference pH value of 7.3, and some reactions have been computationally balanced for hydrogen by adding free protons. Please see the PGDB Concepts Guide for more information.
Mass balance status: Balanced.
Enzyme Commission Primary Name: arylesterase
Enzyme Commission Synonyms: A-esterase, paraoxonase, aromatic esterase
Standard Gibbs Free Energy (ΔrG'° in kcal/mol): 16.255127 [Latendresse13]
Enzyme Commission Summary:
Acts on many phenolic esters. The reactions of EC 22.214.171.124 aryldialkylphosphatase, were previously attributed to this enzyme. It is likely that the three forms of human paraoxonase are lactonases rather than aromatic esterases [Khersonsky05, Draganov05]. The natural substrates of the paraoxonases are lactones [Khersonsky05, Draganov05], with (±)-5-hydroxy-6E,8Z,11Z,4Z-eicostetraenoic-acid 1,5-lactone being the best substrate [Draganov05].
Unification Links: KEGG:R07342
ALDRIDGE53: ALDRIDGE WN (1953). "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(1);110-7. PMID: 13032041
Bosmann72: Bosmann HB (1972). "Membrane marker enzymes. Characterization of an arylesterase of guinea pig cerebral cortex utilizing p-nitrophenyl acetate as substrate." Biochim Biophys Acta 276(1);180-91. PMID: 5047702
Draganov05: Draganov DI, Teiber JF, Speelman A, Osawa Y, Sunahara R, La Du BN (2005). "Human paraoxonases (PON1, PON2, and PON3) are lactonases with overlapping and distinct substrate specificities." J Lipid Res 46(6);1239-47. PMID: 15772423
Mackness87: Mackness MI, Thompson HM, Hardy AR, Walker CH (1987). "Distinction between 'A'-esterases and arylesterases. Implications for esterase classification." Biochem J 245(1);293-6. PMID: 2822017
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