Publications

• Aspirin hydrolyzing esterases from rat liver cytosol.

  Kim D.H., Yang Y.S., Jakoby W.B.

  Unlike most esterases, which are predominantly bound to the microsomal fraction, the enzymes hydrolyzing acetylsalicylic acid are present in an equal amount in the cytosol. Two soluble isozymes were purified to homogeneity from rat liver and characterized as serine esterases with a Mr of 35,000. B ... >> More

  Unlike most esterases, which are predominantly bound to the microsomal fraction, the enzymes hydrolyzing acetylsalicylic acid are present in an equal amount in the cytosol. Two soluble isozymes were purified to homogeneity from rat liver and characterized as serine esterases with a Mr of 35,000. Both had the wide substrate spectrum characteristic of enzymes active in detoxication. Both had a very low Km for acetylsalicylate. Three other cytoplasmic enzymes active with aspirin were observed but these differed in their high Mr (about 220,000) and their lack of reactivity with antibody to one of the homogeneous isozymes. << Less

  Biochem Pharmacol 40:481-487(1990) [PubMed] [EuropePMC]

• Partial purification and characterization of a microsomal carboxylesterase specific for salicylate esters from guinea-pig liver.

  White K.N., Hope D.B.

  Studies on liver carboxylesterases have predominantly involved the use of uncharged ester and amide substrates to monitor activity. A microsomal carboxylesterase (EC 3.1.1.1) from guinea-pig liver microsomes has been identified which specifically hydrolyses aspirin (White, K.N. and Hope, D.B. (198 ... >> More

  Studies on liver carboxylesterases have predominantly involved the use of uncharged ester and amide substrates to monitor activity. A microsomal carboxylesterase (EC 3.1.1.1) from guinea-pig liver microsomes has been identified which specifically hydrolyses aspirin (White, K.N. and Hope, D.B. (1981) Biochem. J. 197, 771-773), a substrate which is negatively charged at physiological pH, and this work describes its partial purification and characterization. The enzyme is monomeric, it has a molecular weight of approx. 55 000 and is very sensitive to inhibition by the carboxylesterase inhibitor bis(4-nitrophenyl)phosphate. Although it could not be completely separated from contaminating carboxylesterases, substrate specificity was investigated using the negatively charged esters of salicylic acid. The enzyme is not specific for the acetyl ester of salicylic acid, aspirin, but hydrolyses the longer chain esters more rapidly, with the highest Vmax for the n-octanoyl ester. The enzyme was subject to substrate inhibition which increased with increasing chain length of the fatty acid on the ester, and approached 100% inhibition at concentrations of substrate below critical micellar concentrations. << Less

  Biochim Biophys Acta 785:138-147(1984) [PubMed] [EuropePMC]

• Mammalian tissue acetylsalicylic acid esterase(s): identification, distribution and discrimination from other esterases.

  Ali B., Kaur S.

  J Pharmacol Exp Ther 226:589-594(1983) [PubMed] [EuropePMC]