Carboxylesterases and Amidases

Heymann, Eberhard

doi:10.1016/b978-0-12-380002-2.50022-1

Cited by 175 publications

(93 citation statements)

References 117 publications

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“…Their molecular weight is similar, ranging from 55 to 70 kDa for many esterases (Heymann, 1980). Esterases with similar molecular weights have been reported in Boophilus microplus (De Jersey et al, 1985), Myzus persicae (Field et al, 1988), Culex quinquefasciastus (Merryweather et al, 1990), Culex tarsalis (Whyard et al, 1994b) and Lucilia cupri-nia (Whyard et al, 1994a).…”

Section: Discussionsupporting

confidence: 56%

Purification and characterization of a carboxylesterase involved in malathion-specific resistance from Tribolium castaneum (Coleoptera: Tenebrionidae)

Haubruge

Amichot²,

Cuany³

et al. 2002

Insect Biochemistry and Molecular Biology

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Specific resistance to malathion in a strain of Tribolium castaneum is due to a 44-fold increase in malathion carboxylesterase (MCE) activity relative to a susceptible strain, whereas non-specific esterase levels are slightly lower. Unlike the overproduced esterase of some mosquito and aphid species, MCE in Tribolium castaneum accounts for only a small fraction (0.033-0.045%) of the total extractable protein respectively in resistant and susceptible strains. The enzyme was purified to apparent homogeneity from these two strains and has a similar molecular weight of 62,000. However, preparative isoelectricfocusing indicated that resistant insects possess one MCE with pI of 7.3, while susceptible insects possess a MCE with a pI of 6.6. Purified MCE from both populations had different K m and V m values for hydrolysis of malathion as well as for α-naphthyl acetate. The kinetic analysis suggests that MCE of resistant insects hydrolyses malathion faster than the purified carboxylesterase from susceptible beetles and that this enzyme has greater affinity for malathion than for naphthyl esters. Malathion-specific resistance is due to the presence of a qualitatively different esterase in the resistant strain.

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Section: Discussionsupporting

confidence: 56%

Purification and characterization of a carboxylesterase involved in malathion-specific resistance from Tribolium castaneum (Coleoptera: Tenebrionidae)

Haubruge

Amichot²,

Cuany³

et al. 2002

Insect Biochemistry and Molecular Biology

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“…It is also reported that mammalian liver carboxylesterases consist of units with a molecular mass of approx. 60 kDa [15]. These findings do not contradict those obtained for GHA deacetylase.…”

Section: Discussioncontrasting

confidence: 33%

“…GHA deacetylase could be classified as a Besterase, defined by Aldridge [41], on the basis of the result that activity was inhibited by organophosphates ( Figure 8 and Table 4) but not by p-chloromercuribenzoate. The pI and pH optima of B-esterases have been reported to be generally in the range of 4.7-6.5 and 7-9 respectively [15]. It is also reported that mammalian liver carboxylesterases consist of units with a molecular mass of approx.…”

Section: Discussionmentioning

confidence: 99%

“…Several findings of the enzymic characterization suggest that GHA deacetylase is a carboxylesterase. The fact that GHA deacetylase showed a high affinity for ConA-Sepharose indicates that the enzyme is a glycoprotein, like many mammalian carboxylesterases [15,16]. GHA deacetylase could be classified as a Besterase, defined by Aldridge [41], on the basis of the result that activity was inhibited by organophosphates ( Figure 8 and Table 4) but not by p-chloromercuribenzoate.…”

Section: Discussionmentioning

confidence: 99%

“…somal amidases\carboxylesterases have been reported to hydrolyse xenobiotics containing ester and amide bonds, and to be involved in their toxification and\or detoxification [15,16].…”

Section: Introductionmentioning

confidence: 99%

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Purification and characterization of guinea-pig liver microsomal deacetylase involved in the deacetylation of the O-glucoside of N-hydroxyacetanilide

Suzuki-Kurasaki

Yoshioka

Uematsu

1997

Biochemical Journal

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A microsomal deacetylase that catalyses the deacetylation of the O-glucoside of N-hydroxyacetanilide (GHA) was purified from guinea-pig liver. The activity was located exclusively in the microsomes and not detected in the cytosol. The purified GHA deacetylase was a trimeric protein with a molecular mass of 160±10 (S.D.) kDa composed of subunits of 53±2 kDa; its pI was 4.7. The N-terminal amino acid sequence of GHA deacetylase was similar to those reported for guinea-pig and rat liver microsomal carboxylesterases. The GHA deacetylase showed a comparable hydrolytic activity towards p-nitrophenyl acetate (PNPA), although the activities towards N-hydroxyacetanilide, acetanilide and some endogenous acylated compounds were very low or not detectable. The deacetylase activity towards GHA was inhibited by organophosphates but not by p-chloromercuribenzoate, suggesting that GHA deacetylase can be classified as a B-esterase. The enzyme exhibited a positive homotropic co-operativity towards GHA. The values of the Hill coefficient, the half-saturating concentration ([S]0.5) for GHA, and Vmax were 1.59±0.03, 5.51±0.07 mM and 32.5±1.4 μmol/min per mg respectively, at the optimum pH of 8.5. The bell-shaped pH dependence of the Vmax/[S]0.5 profile indicated pKa values attributed to histidine and lysine residues. The study of stoichiometric inhibition by di-isopropyl fluorophosphate and kinetic analysis with the Monod–Wyman–Changeux model suggests that GHA deacetylase has six substrate binding sites and three catalytically essential serine residues per enzyme molecule.

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2-(Glucosylthio)ethyl Groups as Potential Biolabile Phosphate- Protecting Groups of Mononucleotides

Schlienger

Philouze

Aubertin

et al. 1999

HCA

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Carboxylesterases and Amidases

Cited by 175 publications

References 117 publications

Purification and characterization of a carboxylesterase involved in malathion-specific resistance from Tribolium castaneum (Coleoptera: Tenebrionidae)

Purification and characterization of a carboxylesterase involved in malathion-specific resistance from Tribolium castaneum (Coleoptera: Tenebrionidae)

Purification and characterization of guinea-pig liver microsomal deacetylase involved in the deacetylation of the O-glucoside of N-hydroxyacetanilide

2-(Glucosylthio)ethyl Groups as Potential Biolabile Phosphate- Protecting Groups of Mononucleotides

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