• Korean journal of applied entomology
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• v.37 no.2
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• pp.179-185
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• 1998

The effect of physiological factors of beet armyworm, Spodoptera exigua (Hubner), on esterase variation was analyzed by comparing electrophoretic esterase isozymes. Each esterase isozyme was also characterized by substrate and inhibitor specificities. A total of 28 esterase isozymes were separated on 10% nondenaturing polycarylamide gel electrophoresis (PAGE). These isozymes were denoted from El to E28 according to cathodal migration distances. There was a variation in esterase isozymes among developmental stages. Larvae and pupae had more isozymes than did adults. Eggs had only eight isozymes. The isozymes of El and E2 were specific only in the first instar larvae. Esterases also showed variation according to different tissues. More kinds of esterase isozymes were found in epidermis and gut tissues than in hemolymph and fat body. Some isozymes were specific in epidermis (from El to E6), gut (E10, El 1, E25, E26, and E27), and hemolymph (E18). Among 10 naphthyl esters, a-naphthyl propionate was the most reactive substrate to the esterase isozymes. The isozymes were classified into cholinesterases (El0 and E24), arylesterases (E4, E9, E17, E19, E21, and E23), and carboxylesterases (the others) on the basis of inhibition by the esterase inhibitors-eserine, dichlorovos, moncrotophos, and paraoxon.

• Journal of fish pathology
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• v.27 no.1
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• pp.25-33
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• 2014

Hydrolase activities of excretory-secretory products (ESP) and somatic extracts (SE) from Anisakis simplex sensu stricto (s.s.) and Anisakis pegreffii larvae were investigated by using API ZYM kit. In esterase group, acid phosphatase showed high activity from both of A. simplex (s.s.) and A. pegreffii. Esterase (C4) showed activity only from SE and A. simplex (s.s.) showed higher activity than A. pegreffii. Alkaline phosphatase, acid phosphatase and naphthol-AS-BI-phosphohydrolase showed higher activity in 3rd stage larvae than in 4th stage larvae of both species. In aminopeptidase group, only leucine arylamidase showed remarkable activity in SE of both anisakid species, and A. simplex (s.s.) SE showed higher activity than A. pegreffii SE. In glycosidase group, N-acetyl-${\beta}$-glucosaminidase, ${\alpha}$-mannosidase, ${\alpha}$-fucosidase showed higher activity in A. simplex (s.s.) than A. pegreffii, and 4th larvae showed higher activity than 3rd larvae. These differences in hydrolase activity of anisakid nematodes larvae are thought to be due to different metabolism such as growth, moulting, digestion and feeding.

• Parasites, Hosts and Diseases
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• v.38 no.1
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• pp.45-48
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• 2000

An enzyme analysis of the liver fluke, Clonorchis sinensis from Kimhae, Korea and from Shenyang, China was conducted using a horizontal. starch gel electrophoresis in order to elucidate their genetic relationships. A total of eight enzymes was employed from two different kinds of buffer systems. Two loci from each enzyme of aconitase and esterase (${\alpha}-Na{\;}and{\;}{\beta}-Na$) : and only one locus each from six enzymes, gluucose-6-phosphate dehydrogenase (G6PD), ${\alpha}-glycerophosphate$ dehydrogenase (GPD), 3-hydroxybutyrate dehydrogenase (HBDH), malate dehydrogenase (MDH), phosphoglucose isomerase (PGI), and phosphoglucomutase (PGM) were detected. Most of loci in two populations of C. sinensis showed homozygous monomorphic banding patterns and one of them, GPD was specific as genetic markers between two different populations. However, esterase (${\alpha}-Na$), GPD, HBDH and PGI loci showed polymorphic banding patterns. Two populations of C. sinensis were more closely clustered within the range of genetic identity value of 0.998-1.0. In summarizing the above results, two populations of C. sinensis employed in this study showed mostly monomorphic enzyme protein banding patterns, and genetic differences specific between two populations.

• Applied Biological Chemistry
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• v.14 no.3
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• pp.229-235
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• 1971

Kwanok, Fujisaka #5, Paldal, and Suwon #82 as japonica type and IR-262 and CP-slo as indica type of rice seeds were selected for this experiment among varieties grown in Korea. Activities of crude enzymes extracted from germinating seeds of these varieties on malathion and p-nitrophenyl acetate as substrates, esterase zymograms with 1-naphthyl acetate as substrate, and some observations are summarized as follows: 1. Activities per unit volume of crude enzyme preparations on malathion were in the order of Kwanok>IR-262>Fujisaka #5>CP-slo>Paldal>Suwon #82. 2. Esterase zymograms on agar-gel electrophoretograms exhibited three to four bands two electrodes with little difference among varieties, nevertheless showing a wide and strongly-colored band toward cathode. Suwon #82 has a somewhat different pattern from others. 3. Enzyme activities per milligram protein with p-nitrophenyl acetate as substrate were in the order of CP-slo>IR-262>Paldal>Kwanok>Suwon #82>Fujisaka #5, indicating that activities of indica type are much stronger than those of japonica type, but not in agreement with results with malathion. 4. Malathion did not much inhibit the esterase activity at the concentration of 0.2PPM on electrophoretograms. 5. It is supposed that there is a complex esterase system hydrolyzing malathion and p-nitrophenyl acetate in germinating rice seeds.

• Korean Journal of Plant Resources
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• v.10 no.4
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• pp.305-313
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• 1997

The effect of acid rain on plant isozyme response was studied with the treatment of simulated acid rain to Pinus densiflora, P. nigida and P. koraiensis for 9 months. The isozyme pattern of $\alpha$-Esterase($\alpha$-Est), Peroxidase(POD) and Glutamate dehydrogenase(GDH) were observed in the control (pH 5.6) and simulated acid rain (pH 3.5) treatment. No changes of isozyme pattern in $\alpha$-Est was observed in P. densiflora after 9 month treatment of simulated acid rain, but, two new isozymes were activated in P. nigida in the same treatment. In P. koraiensis, two new isozyme were activated but five isozymes were not activated. P. densiflora did not show any difference in POD and GDH after the treatment of simulated acid rain. P. nigida showed activation of eight and two isozymes in POD and GDH, respectively. P. koraiensis showed inactivation of 4 isozymes in POD but showed no changes In GDH.

• Korean journal of applied entomology
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• v.25 no.2 s.67
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• pp.99-105
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• 1986

The green peach aphids(Myzus persicae) collected in a field had been successively selected by acephate(O, S-dimethyl N-acetyl phosphoroamidothioate) in the laboratory. The selected aphid strain in the 20th generation demonstrated relatively high resistance to acephate as well as relatively high cross-resistance to cypermethrin and oxydemeton-methyl, except pirimicarb. The different esterase isozymes with the strains were detected by the agarose gel electrophoresis and among the isozymes the band of ${\beta}-2$ was only specific for the acephate resistant strains.

• BMB Reports
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• v.29 no.6
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• pp.500-506
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• 1996

We have isolated a water-extracted novel regulator for blood coagulation from an earthworm, Lumbricus rubellus. As a folk remedy, the earthworm has been known to facilitate blood circulation. After complete heat inactivation of endogenous proteases in the earthworm, an anticoagulant(s) was purified through ammonium sulfate fractionation and three consecutive gel permeation chromatography of Sephacryl S-300, Sephadex G-75, and G-150 by measuring activated partial thromboplastin time (APTT) The anticoagulant was further purified to 2,800 fold with a C4 reversed-phase HPLC This activity was stable under heat ($100^{\circ}C$ for 30 min) and acidic conditions (0.4 N HCl). The effects of this partially purified anticoagulant on thrombin were observed with various substrates such as N${\alpha}$-benzoyl-DL-arginine-p-nitroanilide (BApNA), H-D-phenylalanyl-L-pipecoyl-L-arginine-p-nitroanilide (S-2238), N${\alpha}$-p-tosyl-L-arginine methyl ester (TAME), and fibrinogen as a natural substrate. Only TAME hydrolysis, due to an esterase activity of the enzyme, was inhibited among the chromogenic substrates. In addition, the anticoagulant not only inhibited the conversion of fibrinogen to fibrin but also prolonged the fibrin clot formation monitored with the in vitro coagulation test. Based on these observations, we suggest the significance of measuring the ability of antithrombotic drugs to inhibit the esterase activity of thrombin. In this report, it was also shown that the earthworm indeed contained a water-extractable, heat- and acid-stable anticoagulant which could be used as a novel antithrombotic agent.

• Mycobiology
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• v.46 no.2
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• pp.159-167
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• 2018

This study evaluated the in vitro and in vivo hypolipidemic effects of the medicinal mushroom Phellinus pini. The methanol extract (ME) of the fruiting body of Ph. pini was active against pancreatic lipase and cholesterol esterase with 99.14% and 67.23% inhibited activity at 1.0 mg/mL, respectively. It also inhibited 81.81% and 55.33% of ${\alpha}$-glucosidase and ${\alpha}$-amylase activities, respectively, at 2.0 mg/mL. Hyperlipidemia as induced by feeding rats with a high fat and cholesterol diet (HFC). HFC supplemented with a 5% fruiting body powder of Ph. pini (HFC + PhP) significantly reduced plasma total cholesterol, low-density lipoprotein cholesterol, and triglycerides in rats compared with HFC. The reduced levels were comparable to rats fed the normal control diet (NC). The atherogenic index of HFC + PhP rats was significantly lower than that of the HFC rats. The excretion of fecal total lipid and cholesterol in the HFC + PhP rats was significantly higher than those in the NC and HFC rats. Histopathological examinations demonstrated scant deposition of lipids in the liver of rats fed HFC + PhP. The dietary supplementation with the fruiting body powder provided natural plasma lipid and glucose lowering effects in experimental rats without adverse effects on the plasma biochemical parameters and liver function related enzyme activities. Therefore, the hypolipidemic effects of Ph. pini may be due to the inhibitory effects on pancreatic lipase, cholesterol esterase, ${\alpha}$-glucosidase, and ${\alpha}$-amylase, and excretion of excess lipids and cholesterol in the feces.

• Journal of Microbiology and Biotechnology
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• v.2 no.1
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• pp.1-6
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• 1992

The aspartame, $\alpha$-L-aspartyl-L-phenylalanine methylester, is an artificial sweetener. Taking advantage of the fact that the aspartame is a derivative of dipeptide, synthesis of aspartame from the artificial polypeptide made by an artificial gene has been attempted. The artificial polypeptide (LAP32), a polymer of tripeptide (aspartyl-phenylalanyl-lysine), was purified from the E. coli cells harboring a recombinant plasmid containing the artificial gene. This polypeptide was then digested with trypsin and carboxypeptidase B to produce dipeptide (Asp-Phe). Using the esterase activity of $\alpha$-chymotrypsin, the dipeptide was directly converted into Asp-Phe methylester in a water-methanol system. When the methanol concentration in reaction mixture was 25%, 50% of dipeptide was converted to the dipeptide methylester without producing any by-products.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.662-665
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• 2001

Enantioselective production of levofloxacin from ofloxacin butyl ester by porcine liver esterase was enhanced with the addition of ${\alpha}$-cyclodextrin(${\alpha}-CD$) and pH change. The conversion yield was increased from 27 to 64% and 100% with 150 mM substrate when the molar ratio of ${\alpha}-CD$ to substrate was 1 and 2, respectively. When 100 mM of substrate was added with the same molar ratio of ${\alpha}-CD$ at pH 5.6, the solubility was increased 3.8 times and the conversion yield was increased 4.4 times.