Research on the Determination Method of Enzymatic Activity for β-Glucan Synthase (ΒGS)

2011 ◽  
Vol 396-398 ◽  
pp. 1583-1587 ◽  
Author(s):  
Peng Li ◽  
Wei Guo Wang ◽  
Yu Jia Cui ◽  
Yong Liang Zhao ◽  
Ya Nan Gu

Purpose To research out a suitable method for the determination of enzymatic activity for β-glucan synthase. Methods According to the methods for the determination of ΒGS in current reports, taking Grifola frondosa as material, a suitable method for the determination of enzymatic activity for ΒGS was researched out. ΒGS was isolated from the mycelium of Grifola frondosa. Taking glucose as substrate, ΒGS activity was reflected by the consumption of glucose. Consumption of glucose was measured by 3,5-dinitrosalicylic acid (DNS) method, the standard curve for glucose content measurement was plotted by determining absorbance values of different glucose concentrations at 540nm. One unit of ΒGS corresponds to the amount of enzyme which incorporated 1μg glucose into β-glucan in 1 minute. The optimum pH and temperature of the determination of enzymatic activity for ΒGS was determined respectively by carrying out the enzyme assay at different pH levels and temperatures. Results The method for the determination of enzymatic activity for ΒGS was a suitable, correct and usable method which can be popularized widely. The regression equation of the standard curve for glucose content measurement was y=0.0008x-0.0247, R2=0.9996. The optimum pH of the determination of enzymatic activity for ΒGS was pH=5.0 and the optimum temperature was 15°C. The suitable determination process for β-glucan synthase enzymatic activity is as follows: 1.0ml of enzyme was added in a test tube followed by 1.0 ml glucose (1.0mg/ml), and then the pH level was adjusted to 5.0. The test tube was incubated at 15°C for 10 minutes. Later, DNS reagent (1.5ml) was added to the test tube kept in boiling water for 5 minutes and cooled in water. A blank was prepared (2.0ml distilled water and 1.5ml DNS solution). Each solution was fixed the volume to 25ml, the color intensity was estimated at 540 nm using spectrophotometry. Conclusion A method for the determination of enzymatic activity for β-glucan synthase was researched out by taking Grifola frondosa as material, and it can be widely extended and applied by its characteristics of simple, rapid, high sensitivity and low cost.

1959 ◽  
Vol 36 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Julius A. Goldbarg ◽  
Esteban P. Pineda ◽  
Benjamin M. Banks ◽  
Alexander M. Rutenburg

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Haiyan Lei ◽  
Jianbo Guo ◽  
Zhuo Lv ◽  
Xiaohong Zhu ◽  
Xiaofeng Xue ◽  
...  

This study reports an analytical method for the determination of nitroimidazole and quinolones in honey using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A modified QuEChERS methodology was used to extract the analytes and determine veterinary drugs in honey by LC-MS/MS. The linear regression was excellent at the concentration levels of 1–100 ng/mL in the solution standard curve and the matrix standard curve. The recovery rates of nitroimidazole and quinolones were 4.4% to 59.1% and 9.8% to 46.2% with relative standard deviations (RSDs) below 5.2% and the recovery rates of nitroimidazole and quinolones by the matrix standard curve ranged from 82.0% to 117.8% and 79% to 115.9% with relative standard deviations (RSDs) lower than 6.3% in acacia and jujube honey. The acacia and jujube honeys have stronger matrix inhibition effect to nitroimidazole and quinolones residue; the matrix inhibition effect of jujube honey is stronger than acacia honey. The matrix standard curve can calibrate matrix effect effectively. In this study, the detection method of antibiotics in honey can be applied to the actual sample. The results demonstrated that the modified QuEChERS method combined with LC-MS/MS is a rapid, high, sensitive method for the analysis of nitroimidazoles and quinolones residues in honey.


1994 ◽  
Vol 27 (5) ◽  
pp. 867-878 ◽  
Author(s):  
D. W. Bryce ◽  
J. M. Fernández-Romero ◽  
M. D. Luque de Castro

2000 ◽  
Vol 48 (3) ◽  
pp. 285-291 ◽  
Author(s):  
Klára Oppel ◽  
L. Bárdos ◽  
A. Ferencz ◽  
Hajnalka Lakner ◽  
Judit Simon ◽  
...  

Serum/plasma fructosamine (SeFa) concentration is a reliable indicator used in human diabetic control. Tests for monitoring the carbohydrate/energy metabolism of (farm) animals are less commonly performed in veterinary laboratories, since most of the reliable determinations, both automated and manual, are relatively expensive. The aim of this study was to develop a precise, money- (and time-) saving automated micro method for measuring SeFa. ELISA microplates (20 µL samples and 200 µL reagents) and an automatic microplate autoreader were used. The classical nitroblue tetrazolium (NBT) stain reagent solution of Johnson et al. (1982) was modified using a SIGMA reagent to render it stable for up to one year. SeFa concentrations measured by the new method in 30 human blood plasma samples were compared with values obtained by the standard (generally used) LaRoche kit procedure. Fifteen cow, 13 dog and 18 chicken plasma samples were assayed by the new automated ‘micro’ method as well as by the manual test tube ‘macro’ method commonly used earlier. The modified reagent was applied for both methods. The coefficient of correlation (r) between the results obtained by the two methods was consistently between 0.94 and 0.98 (p < 0.001).


2017 ◽  
Vol 5 (1) ◽  
Author(s):  
Dini Hadiarti

ABSTRACTPremna Serratifolia Linn is believed to reduce cholesterol and as an alternative herbal medicine solution among the cost of medicine and the side effects caused by synthetic drugs. This study was conducted in several phases by using Premna Serratifolia Linn which was drained, mashed, and macerated using ethanol, choloform, and n-heksane. Extract obtained from evaporation, then whighed, and stored in a desiccators. Anti-cholesterol activity was tested test by using in vitro : began with determination of the maximum wavelength of the cholesterol standard solution with a UV-Vis spectrophotometer and continued by manufacturing the standard curve with the cholesterol concentration of 0.5; 0.75; 1; 1.25; and 1.5 mL and 1000 ppm cholesterol solution. Furthermore, maximum absorbance wavelength was measured in order to obtain the maximum wavelength of the cholesterol. The study reveled that the solvent extraction of ethanol produced the largest  rendement. The extract Premna Serratifolia Linn is functioned as an anti-cholesterol. In addition,  the absorbed reduction of 100 ppm cholesterol standard solution found in the addition of 0.5 mL choloform extract.Keywords: Anti-cholesterol, Premna Serratifolia Linn, In Vitro


2018 ◽  
Vol 8 (6-s) ◽  
pp. 182-186
Author(s):  
Vineeta Singh ◽  
Anita Rao ◽  
Shipra Pandey ◽  
Vaibhav Sharan Pandey ◽  
Vageshwari Vageshwari ◽  
...  

The present enquiry was intended to analyze the phytochemicals qualitatively and quantitatively from flowers of Spanish cherry tree. Flower powder was extracted using polar and nonpolar solvent by soxhlet apparatus. Percentage yield of crude extracts was determined and further the extracts were subjected to analyze the phytochemicals qualitatively and quantitatively by standard procedure. Qualitative analysis showed the absence of alkaloids while presences of tannins, saponins, terpenoids, steroids, glycosides, flavonoids, phenols. Quantitative estimation of phytochemicals was determined using standard curve. Result revealed that the tannin content was 4.3±0.01 (mgTAE /gm), flavanols content was 0.28±0.05 (mgQE/gm). Saponins content was 3.6±0.7 % and terpenoids content was 1.47±0.37 %. A well conducted studies on phytochemicals revealed that they are vital for humans because they provide protection against a variety of ailments. Therefore, the present study is aimed to analyze phytochemicals qualitatively and quantitatively. Keywords: Phytochemicals, Tannins, Saponins, Flavanols, Terpenoids


2018 ◽  
Vol 11 (1) ◽  
pp. 1-11
Author(s):  
Hossein Mahboudi ◽  
Negin Mohammadizadeh Heidari ◽  
Zahra Irani Rashidabadi ◽  
Ali Houshmand Anbarestani ◽  
Soroush Karimi ◽  
...  

Background: There are numerous approaches dealing with relative and absolute quantitation. The methods differ in their efficiency assumption and applicability. Objective: Current methodologies and rations used in qPCR quantification were compared in an experimental study of transgenic copy number determination of a monoclonal antibody Daclizumab. Methods: With an inter and intra-methodical view, variations in relative and absolute quantification strategies were discretely extracted and compared to one another. Results: In relative quantification, six methods were studied and the ratios were computed relative to Glucagon as internal control. For Absolute quantification, the calculations were based on standard curve. Relative quantification considers the relative changes in expression levels while Absolute quantification relates the PCR signal to input copy number with a calibration curve. Conclusion: The observed unevenness of the ratios in Relative approach pointed mainly to the efficiency changes and its calculation formula. Whereas results in Absolute approach strategies showed homogeneity which indicates the consistency of the calculation method.


2011 ◽  
Vol 8 (2) ◽  
pp. 896-902
Author(s):  
Seniwati Dali ◽  
A. B. D. Rauf Patong ◽  
M. Noor Jalaluddin ◽  
Pirman ◽  
Baharuddin Hamzah

Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase fromAspergillus oryzae. Lipase was partially purified from the culture supernatant ofAspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of optimum pH, optimum temperature, thermal stability and reusability were carried out. The results showed that free lipase had optimum pH 8,2 and optimum temperature 35 °C while the immobilized lipase had optimum 8,2 and optimum temperature 45 °C. The thermal stability of the immobilized lipase, relative to that of the free lipase, was markedly increased. The immobilized lipase can be reused for at least six times.


1978 ◽  
Vol 8 (5) ◽  
pp. 503-508
Author(s):  
Y Brun ◽  
J Fleurette ◽  
F Forey

We have endeavored to elaborate a suitable method for easy and rapid identification in clinical microbiology laboratories of the different species of infection-inducing, coagulase-negative staphylococci. Ten type strains described by Kloos and Schleifer and 269 strains isolated from 95 patients were tested; the classical tests were used for determination of Staphylococcus species. Strains were identified by using the Kloos-Schleifer reference method and the micromethod simultaneously. After preliminary tests on 77 substrates, 19 were retained, 15 for determination of species and 4 to reveal biotypes. The substrates were placed in wells in a rigid strip of inert plastic. Inoculation of wells was carried out with rich microbial suspensions in a special medium; reading of substrate reactions was done after incubation for 48 h at 35 degree C. The intrasystem reproducibility was excellent, from 91 to 100% for the 19 substrates. It was in excellent agreement with the reference method, 100% for type strains and 97.9% for hospital-isolated strains. Because it is simple and easy to reproduce, the micromethod will be most useful in clinical and ecological microbiology laboratories.


1975 ◽  
Vol 21 (10) ◽  
pp. 1422-1426 ◽  
Author(s):  
Gerald A Moss ◽  
Richard J L Bondar ◽  
Diane M Buzzelli

Abstract Creatinine amidohydrolase is used to measure serum creatinine in a totally enzymatic procedure. Creatine, produced by hydrolysis, is acted upon by creatine kinase, and then by pyruvate kinase and lactate dehydrogenase, to result in a change in absorbance at 340 nm. The amount of creatinine present is related to the rate of change in A340 and is determined from a standard curve. Absorbance and concentration are linearly related to 100 mg/liter and only 250 µl of serum is required. At 1.0 g/liter, heparin, oxalate, citrate, ethylenediaminetetraacetate, ascorbate, or glucose had no significant effect on the accurate determination of creatinine; higher concentrations (30 g/liter) had inhibitory effects on the test. Analytical recovery of creatinine added to either normal or abnormal sera averaged 102%. When results of this procedure and of the standard direct Jaffé test were compared, the latter were significantly higher. Unlike the Jaffé method, the present method of determining creatinine is rapid (about 10 min per test), subject to few or no interfering substances, and requires no serum deproteinization.


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