scholarly journals Predictability of Age to First Egg from Serun Esterase Activity Levels

1970 ◽  
Vol 49 (3) ◽  
pp. 769-774 ◽  
Author(s):  
A.A. Grunder ◽  
E.S. Merritt ◽  
F.K. Kristjansson
Keyword(s):  
Esterase Activity ◽  
Activity Levels

TAMe esterase activity resulting from blood thromboplastin formation

1961 ◽  
Vol 200 (1) ◽  
pp. 143-146 ◽  
Author(s):  
J. L. Koppel ◽  
Dorothy Mueller Hough ◽  
Phyllis M. Arscott ◽  
John H. Olwin
Keyword(s):  
Trypsin Inhibitor ◽  
Esterase Activity ◽  
Coagulation Factors ◽  
Soybean Trypsin Inhibitor ◽  
Activity Levels ◽  
Active Product ◽  
Intermediate Products ◽  
Esterase Activities

TAMe esterase activity levels have been determined on a) purified coagulation factors essential for thromboplastin (TPN) formation, b) various intermediate products formed in the presence of calcium and phospholipid, and c) complete blood thromboplastin. The level of esterase activity was found to increase as TPN formation proceeded through various intermediate stages to the final active product. The esterase activities of intermediate products I and II were practically completely inhibited by soybean trypsin inhibitor (SBTI), whereas that of blood thromboplastin was inhibited only partially. Interaction of product II with plasma Ac-globulin resulted in the most marked increase in esterase activity. The observations made suggest that this increased and SBTI-insensitive activity is not due to the presence of either thrombin or serum Ac-globulin (factor VI). It has been concluded that the observed TAMe esterase activity is due to blood thromboplastin itself and that the latter resembles Milstone's thrombokinase.

Changes in esterases during early embryonic development of Barytelphusa guerini (H. Milne Edwards)

1991 ◽  
Vol 69 (5) ◽  
pp. 1265-1269 ◽  
Author(s):  
V. Lakshmipathi ◽  
M. Sujatha
Keyword(s):  
Thermal Stability ◽  
Esterase Activity ◽  
Relative Proportion ◽  
Heat Denaturation ◽  
Activity Levels ◽  
Freshwater Crab ◽  
Dilution Technique ◽  
Thermal Stability Of ◽  
Qualitative Changes ◽  
Esterase Band

Quantitative and qualitative changes in the levels of activity of esterases are studied in five stages of developing embryos of the freshwater crab Barytelphusa guerini. Esterase activity levels increase enormously as development progresses. Electrophoresis on 7.5% polyacrylamide disc gels reveals seven zones of esterase active bands. Only two of the seven zones of esterases are present in all five stages. These bands show an increase in their activity in stages III–V. Substrate specificity and inhibitor sensitivity of the enzymes were used to classify esterases. The twofold serial dilution technique was employed to estimate the relative proportion of each esterase band observed during electrophoresis. Heat denaturation studies indicate an increase in the thermal stability of the enzyme as development progresses.

scholarly journals Esterase Activity is Affected by Genetics, Age, Insecticide Exposure, and Viral Infection in the Honey Bee, Apis mellifera

2018 ◽  
Author(s):  
Frank D. Rinkevich ◽  
Joseph W. Margotta ◽  
Michael Simone-Finstrom ◽  
Lilia I. de Guzman ◽  
Kristen B. Healy
Keyword(s):  
Viral Infection ◽  
Honey Bee ◽  
Honey Bees ◽  
Esterase Activity ◽  
Pesticide Exposure ◽  
Mite Infestation ◽  
Activity Levels ◽  
Varroa Mite ◽  
Genetic Stock ◽  
Insecticide Exposure

AbstractNon-target impacts of insecticide treatments are a major public and environmental concern, particularly in contemporary beekeeping. Therefore, it is important to understand the physiological mechanisms contributing to insecticide sensitivity in honey bees. In the present studies, we sought to evaluate the role of esterases as the source of variation in insecticide sensitivity. To address this question, the following objectives were completed: 1) Evaluated esterase activity among honey bee stocks, 2) Assessed the correlation of esterase activity with changes in insecticide sensitivity with honey bee age, 3) Established if esterases can be used as a biomarker of insecticide exposure, and 4) Examined the effects of Varroa mite infestation and viral infection on esterase activity.Results indicated that honey bees have a dynamic esterase capacity that is influenced by genetic stock and age. However, there was no consistent connection of esterase activity with insecticide sensitivity across genetic stocks or with age, suggests other factors are more critical for determining insecticide sensitivity. The trend of increased esterase activity with age in honey bees suggests this physiological transition is consistent with enhanced metabolic rate with age. The esterase inhibition with naled but not phenothrin or clothianidin indicates that reduced esterase activity levels may only be reliable for sublethal doses of organophosphate insecticides. The observation that viral infection, but not Varroa mite infestation, reduced esterase activity shows viruses have extensive physiological impacts. Taken together, these data suggest that honey bee esterase activity toward these model substrates may not correlate well with insecticide sensitivity. Future studies include identification of esterase substrates and inhibitors that are better surrogates of insecticide detoxification in honey bees as well as investigation on the usefulness of esterase activity as a biomarker of pesticide exposure, and viral infection.

Production of acetyl xylan esterase by Trichoderma reesei and Schizophyllum commune

1988 ◽  
Vol 34 (6) ◽  
pp. 767-772 ◽  
Author(s):  
P. Blely ◽  
C. R. MacKenzie ◽  
H. Schneider
Keyword(s):  
Trichoderma Reesei ◽  
Esterase Activity ◽  
Extracellular Enzymes ◽  
Carbon Sources ◽  
Schizophyllum Commune ◽  
Resistant Mutant ◽  
Activity Levels ◽  
Acetyl Xylan Esterase ◽  
Low Levels ◽  
C 30

Activity of acetyl xylan esterase, an enzyme that removes acetyl groups from acetyl xylan, was coproduced with that of endoxylanase and endoglucanase in two Trichoderma reesei strains and one Schizophyllum commune strain. The levels of activity of extracellular enzymes were measured during the course of cultivation on different carbon sources. The highest activity levels of acetyl xylan esterase were produced by T. reesei QM 9414 in a xylan plus cellulose medium and by S. commune in a cellulose medium. Both strains produced low levels of acetyl xylan esterase activity in glucose, xylose, and cellobiose media. Schizophyllum commune also produced low levels of acetyl xylan esterase activity in xylan and acetyl xylan media. Trichoderma reesei RUT C-30 behaved like a catabolite repression resistant mutant and produced higher enzyme levels than the QM 9414 strain on all carbon sources examined. Analytical gel electrophoresis and isoelectric focusing demonstrated that the acetyl xylan esterase activity of S. commune was represented as one major form (pI 3.4) which also hydrolyzed 4-methylumbelliferyl acetate. The esterase systems of T. reesei strains were found to be more complex than those of S. commune. The pattern of coproduction of the various activities suggested that acetyl xylan esterase is a component of the cellulolytic system of the fungi tested.

Improvement of cytoprotective and antioxidant activity of Rosa canina L. and Salix alba L. by controlled differential sieving process against H2O2-induced oxidative stress in mouse primary splenocytes

2017 ◽  
Vol 87 (3-4) ◽  
pp. 191-200 ◽  
Author(s):  
Nidhal Soualeh ◽  
Aliçia Stiévenard ◽  
Elie Baudelaire ◽  
Rachid Soulimani ◽  
Jaouad Bouayed
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Biological Activities ◽  
Good Alternative ◽  
Activity Levels ◽  
Salix Alba ◽  
Rosa Canina ◽  
Free Process ◽  
Plant Powders ◽  
Sieving Process

Abstract. In this study, cytoprotective and antioxidant activities of Rosa canina (RC) and Salix alba (SA), medicinal plants, were studied on mouse primary splenocytes by comparing Controlled Differential Sieving process (CDSp), which is a novel green solvent-free process, versus a conventional technique, employing hydroethanolic extraction (HEE). Thus, preventive antioxidant activity of three plant powders of homogeneous particle sizes, 50–100 µm, 100–180 µm and 180–315 µm, dissolved directly in the cellular buffer, were compared to those of hydroethanolic (HE) extract, at 2 concentrations (250 and 500 µg/mL) in H2O2-treated spleen cells. Overall, compared to HE extract, the superfine powders, i. e., fractions < 180 µm, at the lowest concentration, resulted in greater reactive oxygen species (ROS) elimination, increased glutathione peroxidase (GPx) activity and lower malondialdehyde (MDA) production. Better antioxidant and preventive effects in pre-treated cells were found with the superfine powders for SA (i. e., 50–100 µm and 100–180 µm, both p < 0.001), and with the intermediate powder for RC (i. e., 100–180 µm, p < 0.05) versus HE extract. The activity levels of catalase (CAT) and superoxide dismutase (SOD) in pretreated splenocytes exposed to H2O2, albeit reduced, were near to those in unexposed cells, suggesting that pretreatment with the fine powders has relatively restored the normal levels of antioxidant-related enzymes. These findings supported that CDSp improved the biological activities of plants, avoiding the use of organic solvents and thus it could be a good alternative to conventional extraction techniques.

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