GalT Assay Mixture

2015 ◽  
Vol 2015 (6) ◽  
pp. pdb.rec084194
Keyword(s):  
Assay Mixture

scholarly journals Activation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase in homogenates of developing rat brain

1979 ◽  
Vol 182 (2) ◽  
pp. 367-370 ◽  
Author(s):  
W A Maltese ◽  
J J Volpe
Keyword(s):  
Rat Brain ◽  
Cholesterol Synthesis ◽  
Specific Activity ◽  
Postnatal Period ◽  
Developing Brain ◽  
Brain Maturation ◽  
Assay Mixture ◽  
Coa Reductase ◽  
Developing Rat ◽  
Homogenization Medium

The specific activity of 3-hydroxy-3-methylglutaryl-CoA reductase increases when homogenates of developing rat brain are incubated at 37 degrees C or kept on ice. This increase is completely blocked by the addition of F- to the homogenization medium and the assay mixture. The capacity for activation of the reductase is greatest during the early postnatal period and declines as brain maturation proceeds. The data suggest that catalytic modification of the reductase may play a role in the regulation of cholesterol synthesis in the developing brain.

Shortened Radioimmunoassay for Human Growth Hormone

1974 ◽  
Vol 20 (3) ◽  
pp. 389-391 ◽  
Author(s):  
S L Twomey ◽  
J M Beattie ◽  
G T Wu
Keyword(s):  
Growth Hormone ◽  
Human Growth Hormone ◽  
Rank Correlation ◽  
Human Growth ◽  
Statistical Test ◽  
Sign Test ◽  
Assay Mixture ◽  
Signed Rank ◽  
Significant Difference ◽  
Two Temperatures

Abstract We report a radioimmunoassay procedure for human growth hormone in serum, in which the assay mixture is incubated at 37 °C for a total of 5 h rather than at 4 °C for 48 h. There was no significant difference in results by the two methods, according to the Sign Test and the signed-rank statistical test of Wilcoxin. A comparison of results at the two temperatures demonstrated a Spearmann coefficient of rank correlation value of 0.94. With this facilitation, a laboratory can provide results on the same day that the sample arrives.

An experimental study of the effect of zinc on the activity of angiotensin converting enzyme in serum.

1985 ◽  
Vol 31 (4) ◽  
pp. 581-584 ◽  
Author(s):  
P G Reeves ◽  
B L O'Dell
Keyword(s):  
Experimental Study ◽  
Angiotensin Converting Enzyme ◽  
Zinc Concentration ◽  
Converting Enzyme ◽  
Dietary Zinc ◽  
Assay Mixture ◽  
The Mean ◽  
Ace Activity

Abstract The activity in serum of zinc-dependent angiotensin converting enzyme (ACE), is measured to aid in diagnosis and monitor treatment of certain diseases. This report shows the effect of dietary zinc deprivation on ACE activity in the serum of rats. The mean (and SE) of the zinc concentration (mumol/L) in serum was 3.5 (0.3) in rats deprived of dietary zinc for four days, 16.3 (0.2) in control rats, and 19.8 (0.9) in rats deprived of zinc for four days, then repleted with zinc for 12 h. The respective mean (and SE) of ACE activities (nmol/mL per min) in serum were 390 (15), 543 (13), and 545 (20). Serum ACE activity was restored also by adding zinc to the assay mixture in vitro. The Vmax for ACE was 1.4 times greater when serum was diluted 40-fold as compared with twofold dilution. There was a small effect on the Km for the substrate, but the Km for zinc was decreased by 22-fold when serum was diluted 40-fold. The Vmax under these conditions was decreased by only 9%.

scholarly journals Hydrolytic and alcoholytic dephosphorylation of nucleotides by acid phosphatase in the presence of ethanol

1971 ◽  
Vol 124 (1) ◽  
pp. 189-192 ◽  
Author(s):  
M. Tomaszewski ◽  
J. Buchowicz
Keyword(s):  
Acid Phosphatase ◽  
Inorganic Phosphate ◽  
Wheat Germ ◽  
Assay Mixture ◽  
Enzyme Substrates

The effect of ethanol on the activity of acid phosphatase from wheat germ was studied, by using ribonucleoside monophosphates as the enzyme substrates. The nucleotides were effectively degraded to the corresponding nucleosides in the presence of ethanol at all concentrations tested, including a 96% (v/v) solution. However, the nucleotide dephosphorylation was accompanied by the liberation of orthophosphate only when the concentration of ethanol in the assay mixture did not exceed 15%. No inorganic phosphate was liberated when ethanol was present at higher concentrations. Instead, monoethyl phosphate was formed in quantities expected for orthophosphate. The results are explained in terms of phosphatase-catalysed alcoholysis.

scholarly journals Cloning and Overexpression of Strictosidine β-D-Glucosidase GeneShort Sequence from Catharanthus Roseus in Escherichia coli

2019 ◽  
Vol 9 (4) ◽  
pp. 655-661 ◽  
Author(s):  
Ahmed Saeed Arafa ◽  
Amany Elsayed Ragab ◽  
Abdel-Rahim Sayed Ibrahim ◽  
Wael Saad Abdel-Mageed ◽  
Mahmoud Emam Nasr
Keyword(s):  
Escherichia Coli ◽  
Catharanthus Roseus ◽  
Total Alkaloid ◽  
Active Form ◽  
Peptide Sequence ◽  
Short Sequence ◽  
Assay Mixture ◽  
Conserved Sequence ◽  
Ms Analysis ◽  
Key Enzyme

Purpose: Strictosidine-β-D-glucosidase (SGD) is considered as a key enzyme in the productionof bisindole alkaloids in Catharanthus roseus. The present study illustrated the production of ashort sequence of this enzyme in Escherichia coli without codon optimization.Methods: Strictosidine-β-D-glucosidase (sgd) gene short sequence (1434 bp), which lacksthe conserved sequence KGFFVWS and the localization peptide sequence at the C-terminal,was amplified from cDNA of C. roseus leaves, cloned and expressed in Escherichia coli. Theactivity of the produced protein in cell free lysate was tested using total alkaloid extract of C.roseus leaves.Results: HPLC and LC-MS analysis of the assay mixture revealed the disappearance of thestrictosidine peak.Conclusion: SGD short sequence can be produced in Escherichia coli in active form withoutcodon optimization.<br />

Degradation of Glutathione in Plant Cells: Evidence against the Participation of a γ-Glutamyltranspeptidase

1985 ◽  
Vol 40 (1-2) ◽  
pp. 29-33 ◽  
Author(s):  
Reinhard Steinkamp ◽  
Heinz Rennenberg
Keyword(s):  
Ammonium Sulfate ◽  
Plant Cells ◽  
Artificial Substrate ◽  
Sulfur Source ◽  
Tobacco Cell ◽  
Tobacco Cells ◽  
Assay Mixture ◽  
Feeding Experiments ◽  
Low Rate

When γ-glutamyltranspeptidase activity in tobacco cells was measured using the artificial substrate γ-glutamyl-p-nitroanilide, liberation of p-nitroaniline was not reduced, but stimulated by addition of glutathione. Therefore, glutathione was not acting as a donator, but as an acceptor of γ-glutamyl moieties in the assay mixture, suggesting that γ-glutamvltranspeptidase is not participating in degradation of glutathione. Feeding experiments with [35S-cys]glutathione sup­ported this conclusion. When tobacco cells were supplied with this peptide as sole sulfur source, glutathione and γ-glutamylcysteine were the only labelled compounds found inside the cells. The low rate of uptake of glutathione apparently prevented the accumulation of measurable amounts of radioactivity in the cysteine pool. A γ-glutamylcyclotransferase, responsible for the conversion of γ-glutamylcysteine to 5-oxo-proline and cysteine was found in ammonium sulfate precipitates of tobacco cell homogenates. The enzyme showed high activities with γ-glutamylmethionine and γ-glutamylcysteine, but not with other γ-glutamyldipeptides or glutathione. From these and previously published experiments [(Rennenberg et a!., Z. Naturforsch. 35c, 708-711 (1980)], it is concluded that glutathione is degraded in tobacco cells via the following pathway: γ-glu-cys-gly → γ-glu-cys → 5-oxo-proline → glu.

Activation of alanine aminotransferase in serum by pyridoxal phosphate.

1977 ◽  
Vol 23 (2) ◽  
pp. 175-177 ◽  
Author(s):  
V Lustig
Keyword(s):  
Enzyme Activities ◽  
Alanine Aminotransferase ◽  
Pyridoxal Phosphate ◽  
Absolute Amount ◽  
Phosphate Solution ◽  
Aminotransferase Activity ◽  
Assay Mixture ◽  
Wide Range ◽  
The Absolute ◽  
Alanine Aminotransferase Activity

Abstract Alanine aminotransferase activity in serum increases significantly when serum is incubated with pyridoxal phosphate. The increase depends on the L-alanine concentration in the final assay mixture, being greatest at 800 mmol/liter. Preincubation of 22 normal sera, in a 10:1 ratio with an 8.09 mmol/liter pyridoxal phosphate solution, resulted in an increase in the alanine aminotransferase activity from 10.5 +/- 4.9 U/liter (mean +/- SD) to 28.4 +/- 5.3 U/liter, an increase of 170%. The absolute amount of apoalanine aminotransferase is relatively constant over a wide range of enzyme activities.

A sensitive manual enzyme immunoassay for thyroxine.

1978 ◽  
Vol 24 (10) ◽  
pp. 1801-1804 ◽  
Author(s):  
R F Schall ◽  
A S Fraser ◽  
H W Hansen ◽  
C W Kern ◽  
H J Tenoso
Keyword(s):  
Horseradish Peroxidase ◽  
Enzyme Immunoassay ◽  
Specific Antibody ◽  
Limit Of Detection ◽  
Latex Particles ◽  
Assay Mixture ◽  
Coefficients Of Variation ◽  
Assay Performance ◽  
Covalently Bonded

Abstract We describe an immunoassay for thyroxine in serum. In the assay specific antibody covalently bonded to latex particles is used, along with horseradish peroxidase as the label, and o-phenylenediamine as the chromogen. The flexible protocol is designed for manual execution. Performance is similar to that of the highest-sensitivity thyroxine radioimmunoassays. Results correlate well with radioimmunoassay (r = 0.99, slope = 0.93, y-intercept = 2.4 microgram/liter for 201 samples) and an automated enzyme immunoassay (r = 0.97, slope = 0.99, y-intercept = 4.7 coefficients of variation are less than 7.2% over the entire useful range of the assay (20--240 microgram/liter). The limit of detection is less than 94 pg/tube at 20 microgram/liter. Only D-thyroxine is known to interfere with serum assays. This assay has no discernible protein effect from 40 to 80 g of protein per liter, unlike many thyroxine radioimmunoassays. Serum preservatives known to be peroxidase inhibitors do not adversely affect assay performance because of the 56-fold dilution in the final assay mixture. Hemolyzed serum and EDTA-treated plasmas are unsuitable for this assay.

Effect of cations on the human creatine kinase isoenzymes.

1980 ◽  
Vol 26 (8) ◽  
pp. 1137-1139 ◽  
Author(s):  
D A Nealon ◽  
A R Henderson
Keyword(s):  
Creatine Kinase ◽  
Human Tissues ◽  
Assay Mixture ◽  
Creatine Kinase Isoenzymes

Abstract We report our findings on the effect of Ca2+, K+, Na+, Fe2+, Mn2+, Zn2+, and Cu2+ on the activity of creatine kinase isoenzymes derived from human tissues. The only inhibitory cation was Ca2+, and Dixon plots of the data indicate the inhibition to be competitive for the Mg2+ in the reaction assay mixture. This effect of Ca2+ on all three isoenzymes is completely reversed by including Mg2+ (10 mmol/L) and ethylenediaminetetraacetate (2 mmol/L) in the assay mixture. Our findings suggest that it is unnecessary to add chelators to the patient's sample.

Interference of coumarin therapy with the "Heptest" owing to declining prothrombin concentrations.

1989 ◽  
Vol 35 (3) ◽  
pp. 483-486 ◽  
Author(s):  
J Fischer ◽  
B Verbruggen ◽  
H Wessels ◽  
C Haanen
Keyword(s):  
Factor Xa ◽  
Plasma Samples ◽  
Clotting Time ◽  
Assay Mixture ◽  
Normal Plasma

Abstract The Heptest kit (Haemachem, Inc., St. Louis, MO) for quantifying heparin in plasma is based on heparin-mediated inhibition of factor Xa, resulting in prolongation of clotting time. In 19 of 55 plasma samples obtained from 32 patients concurrently receiving coumarin and heparin, Heptest results exceeded true heparin values by more than 0.2 int. unit/mL; four samples showed a deviation exceeding 0.4 int. unit/mL. We show here that these deviations are caused by coumarin-induced decreases of plasma prothrombin. This problem can be circumvented by adding purified prothrombin or normal plasma to the assay mixture.

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