• 한국응용곤충학회지
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• 제32권3호
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• pp.348-353
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• 1993

포장의 약제저항성 변동요인을 조사하기 위하여 복수아혹진딧물의 Carboxyl esterase(CE) 활서측정에 의한 저항성도의 변동상황을 조사하였다. 비닐하우스에서 고추육묘중 발생한 복수아혹진딧물의 CE활성 측정 결과 약제저항성도는 무처리구가 40이였으나 아세페이트를 처리한구는 78로 약제처리로 인한 저항성도가 38이 증가하였다. 또한 노천망실에서 약제처리를 하지 않고 재배한 케일에 발생한 복숭아혹진딧물의 CE활성에 의한 저항성도는 7월이 24이었으나, 8, 9월의 활성이 계속 증가하여 10월이 83으로서 최고에 달하였다가 11월에는 다시 81에서 79로 약천 떨어지고 있어 약제이외에 저항성도의 자연변동요인이 있음을 확인하였다. 전국적으로 18개장소에서 채집한 진딧물의 CE활성을 측정한 결과 저항성도의 평균이 여름은 50$\pm$14였으며 늦가을인 11월은 82$\pm$10으로서 여름보다 늦가을인 11월이 32가 높았으며 그중에도 약제를 살포사지 않은 곳 보다 약제살포 회수가 많은 곳일수록 높았다.

• 한국동물학회지
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• 제39권2호
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• pp.190-197
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• 1996

The optimal conditions and substrate specificity of whole body esterase (EST) activity, effects of inhibitors (Eserine, Paraoxon, p-HMB, DDVP, DFP) on the enzyme, and ontogenv of the isozymes were determined in Lucilio ilfustris Meisen. The optimal temperature was $45^{\circ}C$ regardless of kind of reacted substrate, $\alpha-naphthyl$ acetate $(\alpha-Nal,$ a.naphthvl butylate $(\alpha-N),$ and Pnaphthyl acetate $(\beta-Na),$ but the optimal pH showed some regioselectivitv to naphthvl group of the esters; PH 7.0 for Iform, pH 7.5 for a-form. The maximum reaction rate was recorded at about 2.5 $\times$ 10's M of PNa and etNa, but 1.0 $\times$ 10'S M of $\alpha-Nb.$ Among the five EST inhibitors tested, DDVP was the most powerful. However, distinction of the relative specificity of inhibitors between three body parts, head, thorax, and abdomen, was shouts, representing differences in the distribution and activity of isozvmes. Of 12 carboxyl-esterases (CE), 8 cholinesterases (ChE) and 2 arvlesterases (ArE) identified based on their inhibitor specificity throughout the development, two larval and prepupal stage specific ChEs, no pupal specific, and 2 CEs.2ChEs. and one ArE adult specific isozvmes were confirmed.

• Journal of Microbiology and Biotechnology
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• 제7권1호
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• pp.37-42
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• 1997

A bacterial strain L1 producing a thermostable esterase was isolated from soil taken near a hot spring and identified as Bacillus stearothermophilus by its microbiological properties. The isolated thermostable esterase was purified by ammonium sulfate fractionation, ion .exchange and hydrophobic interaction chromatographies. The molecular weight of the purified enzyme was estimated to be 50,000 by SDS-PAGE. Its optimum temperature and pH for hydrolytic activity against PNP caprylate were $85^{\circ}C$ and 9.0, respectively. The purified enzyme was stable up to $70^{\circ}C$ and at a broad pH range of 4.0-11.5 in the presence of bovine serum albumin. The enzyme was inhibited by phenylmethylsulfonyl fluoride and diethyl p-nitrophenyl phosphate, indicating the enzyme is a serine esterase. The enzyme obeyed Michaelis-Menten kinetics in the hydrolysis of PNPEs and had maximum activity for PNP caproate ($C_6$) among PNPEs ($C_2-C_12$) tested.

• BMB Reports
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• 제32권4호
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• pp.331-338
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• 1999

Ethanol catabolism is thought to produce metabolic disorders resulting in alcoholic liver disease. To investigate the mutual effects of ethanol catabolism and cholestasis induced by common bile duct ligation on the activities of carboxylesterase, we have determined the enzyme activities in rat hepatic (cytosolic, mitochondrial, and microsomal) preparations as well as in rat serum using ten animal models: normal rats (group 1), sham-operated rats (group 2), common bile duct-ligated rats (group 3), ethanol-intoxicated rats (group 4), sham-operation plus chronic ethanol-intoxicated rats (group 5), common bile duct-ligated plus chronic ethanol-intoxicated rats at 1.5h and 24h (groups 7A and 7B), and duct-ligated and acute ethanol intoxicated rats at 1.5 h and 24 h (groups 8A and 8B). The $K_m$ and $V_{max}$ values of carboxylesterase from these hepatic preparations of cholestatic rat liver combined with chronic ethanol intoxication were also measured by using ethyl valerate as the substrate from the 14th day post-ligation. Carboxylesterase activities of all hepatic preparations and rat serum (group 3) showed significant decreases compared to the activities from the sham-operated control (group 2). Enzyme kinetic parameters indicated that $V_{max}$ of carboxylesterase from all the hepatic preparations in cholestatic rats (group 3) decreased significantly, although the $K_m$ values were about the same as in the sham-operated control (group 2). When cholestasis was combined with chronic ethanol intoxication (group 6), carboxylesterase activities showed further decrease in all the hepatic preparations and serum compared to the control activity (group 5). The $V_{max}$ also decreased significantly, although $K_m$ values did not change. When common bile duct ligation was combined with acute ethanol intoxication (group 8), the enzyme activities in the rat liver and serum showed significant decrease compared to the activity from acute ethanol-intoxicated rats (group 7). However, quite contrary to this, the activities of serum from acute ethanol intoxication 1.5 h (group 7A) increased significantly compared to the activities in the normal control (group 1). These results, therefore, suggest that the biosynthesis of hepatic carboxyl-esterase seems to decrease when cholestasis is combined with chronic and acute ethanol intoxication, and the decrease in activity is more significant than from cholestasis alone.