Esterase

negatively . Some of glycoproteins have the ability to affect the cytoplasmic polarity during spore germination and impede cell polarization by inhibiting the protrusion of the germ tube and spore germination. The inhibition of teliospore germination constitutes a defense mechanism involved in the resistance of sugarcane to smut .

A collection of Culex pipiens from Boussalem, Northwestern Tunisia, with a low level of temephos resistance (14.90 at LD95) was selected to higher resistance with temephos in the laboratory. After 6 generations of pressure, the temephos resistance ratio increased to 103.95 at LD95. Synergism tests showed that temephos resistance was not associated with monooxygenase and esterases or (GST); however, evidence of insensitive acetylcholinesterase was found. It is evident that this important vector species, Culex pipiens, has the potential to develop resistance to temephos.

The total protein and esterase were isolated from the seeds of Red Kidney beans (Phaseolus vulgaris). The crude protein content was observed as 15%. The germination of seeds of red kidney bean has been carried out and change in the total protein content and esterase activity was monitored. The protein content was decreased from 15% (24 hours) to 8% (144 hours) during germination. The socked seeds and seedlings of all the days of germination exhibited esterase activity. Maximum ester hydrolyzing activity was observed on 6th day of germination whereas as lowest ester hydrolyzing activity was observed 2nd day germination. Native PAGE was carried out and esterase banding pattern for two different artificial substrates was studied. The esterase banding pattern in presence of 1-Napthyl acetate showed the presence of 4 esterolytic bands while 2 esterolytic bands were observed in presence of 2-Napthyl acetate.

The involvement of hyperactive polyisoprenylated proteins in cancers has stimulated the search for drugs to target and suppress their excessive activities. Polyisoprenylated methylated protein methyl esterase (PMPMEase) inhibition has been shown to modulate polyisoprenylated protein function. For PMPMEase inhibition to be effective against cancers, polyisoprenylated proteins, the signaling pathways they mediate and/or PMPMEase must be overexpressed, hyperactive and be involved in at least some cases of cancer. PMPMEase activity in lung cancer cells and its expression in lung cancer cells and cancer tissues were investigated. PMPMEase was found to be overexpressed and significantly more active in lung cancer A549 and H460 cells than in normal lung fibroblasts. In a tissue microarray study, PMPMEase immunoreactivity was found to be significantly higher in lung cancer tissues compared to the normal controls (p < 0.0001). The mean scores ± SEM were 118.8 ± 7.7 (normal), 232.1 ± 25.1 (small-cell lung carcinomas), 352.1 ± 9.4 (squamous cell carcinomas), 311.7 ± 9.8 (adenocarcinomas), 350.0 ± 24.2 (papillary adenocarcinomas), 334.7 ± 30.1 (adenosquamous carcinomas), 321.9 ± 39.7 (bronchioloalveolar carcinomas), and 331.3 ± 85.0 (large-cell carcinomas). Treatment of lung cancer cells with L-28, a specific PMPMEase inhibitor, resulted in concentration-dependent cell death (EC 50 of 8.5 μM for A549 and 2.8 μM for H460 cells). PMPMEase inhibition disrupted actin filament assembly, significantly inhibited cell migration and altered the transcription of cancer-related genes. These results indicate that elevated PMPMEase activity spur cell growth and migration, implying the possible use of PMPMEase as a protein biomarker and drug target for lung cancer.

A trial was carried out to estimate the LC50 and esterase activity of Apis mellifera L. honeybees after the application of the insecticide thiamethoxam. In insects this product mimics acetylcholine at the central system ganglia. The estimated LC50 were as follows: for oral toxicity: 4.70 x 10-5, 7.40 x 10-5, 8.14 x 10-5, 10.10x10-5 mg/mL for the ages of newly emerged, 7, 14 and 21 days, respectively; for contact toxicity, 3.21, 3.50 and 4.51 mg/mL for newly emerged individuals and for the ages of seven and 14 days, respectively. Electrophoretic analysis showed a decrease in the activity of esterases 1, 2, 4 and 5 due to contact and oral toxicity, suggesting that alteration in the activity of those isozymes can be used to detect the presence of insecticide thiamethoxam pesticide residues.

The present study characterized the ability of a bacterial cutinase to improve the wettability of raw cotton fabrics by specific hydrolysis of the cutin structure of the cuticle. The effect of cutinase was studied alone and in coreaction with pectin lyase. The changes in both the fabric and the reaction fluid were measured and compared to enzymatic hydrolysis with polygalacturonase, and to chemical hydrolysis with boiling NaOH. Water absorbancy, specific staining, fabric weight loss, and evaporative light-scattering reversephase high-performance liquid chromatography analysis of chloroform extract of the reaction fluid were measured to assess the enzymatic hydrolysis of the cuticle waxy layer. The pattern and extent of hydrolysis of the major cuticle constituents depended on the enzyme type and titers employed and paralleled the degree of wettability obtained. The combination of cutinase and pectin lyase resulted in a synergistic effect. The use of detergents improved enzymatic scouring. The major products released to the reaction medium by the cutinase treatment were identified by gas chromatography/mass spectrometry analysis as C:16 and C:18 saturated fatty acid chains.

changes in the relative activity of A. mellifera esterases after application of different sublethal concentrations of the insecticides (methylparathion and malathion) in hives have been evaluated. Homogenates of adult workers were collected in experimental colonies 1, 7, 14 and 21 days after insecticide application. Horizontal eletrophoresis was carried out on 14% corn starch gel using tris-HCl buffer (0.1M Tris) pH 7.5. The esters substrates 4-methylumbelliferyl and @naphtyl were used. Sublethal exposition to the insecticides provides information on the ecological impact of these pesticides on the pollinators. Esterases 3 and 4 of A. mellifera from 1 to 14 days after insecticide application may be used as methyl-parathion and malathion bioindicators, since they reveal outstanding activity alterations when compared to the control.

This study focuses on esterase variation of the genus Crocidura in Turkey. A total of 248 white-toothed shrews were analyzed by means of cellulose acetate gel electrophoresis. Liver tissue and alfa naphthyl acetate were used to investigate esterase variation in Turkish white-toothed shrews. A different esterase banding pattern was found in one Crocidura individual. This phenotype had four anodally migrated bands on cellulose acetate gel. The Crocidura individual displaying the given phenotype was identified as Crocidura suaveolens. The different esterase banding pattern observed in this study is considered to be a result of the trimeric structure of esterase in the lesser white-toothed shrew (Crocidura suaveolens).

The study was undertaken to compare the electrophoretic banding patterns of esterase isozyme between the pupae of Bactrocera papayae and Bactrocera carambolae (Diptera: Tephritidae) by using polyacrylamide gel. These two Bactrocera species are the major agricultural pests, especially fruits and vegetables. One esterase band, EST-1 was detected and the relative mobility value was 0.15 which was close to the cathode. The EST-1 band was present in the pupae of both Bactrocera species. There was no difference in the esterase patterns of both species. The thickness and activation of the band varied slightly. So, the results prove that the pupae of the two Bactrocera species have almost similar esterase band pattern in the same polyacrylamide gel.

Porcine ear skin is widely used to study skin permeation and absorption of ester compounds, whose permeation and absorption profiles may be directly influenced by in situ skin esterase activity. Importantly, esterase distribution and activity in porcine ear skin following common protocols of skin handling and storage have not been characterised. Thus, we have compared the distribution and hydrolytic activity of esterases in freshly excised, frozen, heated and explanted porcine ear skin. Using an esterase staining kit, esterase activity was found to be localised in the stratum corneum and viable epidermis. Under frozen storage and a common heating protocol of epidermal sheet separation, esterase staining in the skin visibly diminished. This was confirmed by a quantitative assay using HPLC to monitor the hydrolysis of aspirin, in freshly excised, frozen or heated porcine ear skin. Compared to vehicle-only control, the rate of aspirin hydrolysis was approximately three-fold higher in the presence of freshly excised skin, but no different in the presence of frozen or heated skin. Therefore, frozen and heat-separated porcine ear skin should not be used to study the permeation of ester-containing permeants, in particular co-drugs and pro-drugs, whose hydrolysis or degradation can be modulated by skin esterases.

Changes in the relative activity of A. mellifera esterases after application of different sublethal concentrations of the insecticides (methyl-parathion and malathion) in hives have been evaluated. Homogenates of adult workers were collected in experimental colonies 1, 7, 14 and 21 days after insecticide application. Horizontal electrophoresis was carried out on 14% corn starch gel using tris-HCl buffer (0.1M Tris) pH 7.5. The esters substrates 4-methylumbelliferyl and α-naphthyl were used. Sublethal exposition to the insecticides provides information on the ecological impact of these pesticides on the pollinators. Esterases 3 and 4 of A. mellifera from 1 to 14 days after insecticide application may be used as methyl-parathion and malathion bioindicators, since they reveal outstanding activity alterations when compared to the control.

A method that allows the measure of molecular weight of two well-known and closely related esterases from Drosophila mojavensis and its sibling species, D. arizonae, is here described, using native polyacrylamide gel electrophoresis at several concentrations, applying Fergunson´s principles. These enzymes, namely EST-4 and EST-5, presented molecular weight values between 81 and 91 kDa. In spite of their distinct expression pattern through the insect's life cycle, they showed properties of isoenzymes codified by distinct structural genes, supporting the hypothesis of a rather recent gene duplication event that generated both in D. mojavensis and D. arizonae, as well as in other species of repleta group. The method is simple and adequate to be applied to preliminary molecular weight determination of other enzymes without any previous purification procedure.

The present study characterized the ability of a bacterial cutinase to improve the wettability of raw cotton fabrics by specific hydrolysis of the cutin structure of the cuticle. The effect of cutinase was studied alone and in coreaction with pectin lyase. The changes in both the fabric and the reaction fluid were measured and compared to enzymatic hydrolysis with polygalacturonase, and to chemical hydrolysis with boiling NaOH. Water absorbancy, specific staining, fabric weight loss, and evaporative light-scattering reversephase high-performance liquid chromatography analysis of chloroform extract of the reaction fluid were measured to assess the enzymatic hydrolysis of the cuticle waxy layer. The pattern and extent of hydrolysis of the major cuticle constituents depended on the enzyme type and titers employed and paralleled the degree of wettability obtained. The combination of cutinase and pectin lyase resulted in a synergistic effect. The use of detergents improved enzymatic scouring. The major products released to the reaction medium by the cutinase treatment were identified by gas chromatography/mass spectrometry analysis as C:16 and C:18 saturated fatty acid chains.

A trial was carried out to estimate the LC50 and esterase activity of Apis mellifera L. honeybees after the application of the insecticide thiamethoxam. A nicotinoid compound, this product mimics the inhibitory action of organophosphates on acetylcholinesterase activity. The estimated LC50 were as follows: for oral toxicity: 4,70 x 10-5, 7.40 x 10-5, 8.14 x 10-5, 10,10x10-5 mg/mL for the ages of newly emerged, 7, 14 and 21 days, respectively; for contact toxicity, 3.21, 3.50 and 4.51 mg/mL for newly emerged individuals and for the ages of seven and 14 days, respectively. Electrophoretic analysis showed a decrease in the activity of esterases 1, 2, 4 and 5 due to contact and oral toxicity, suggesting that alteration in the activity of those isozymes can be used to detect the presence of insecticide thiamethoxam pesticide residues.