Enzyme Assay, Modified Milk-Clotting Procedure for Determination of Papain Activity

1956 ◽  
Vol 4 (4) ◽  
pp. 349-352 ◽  
Author(s):  
Oscar Gawron ◽  
Frank Draus
Keyword(s):  
Enzyme Assay ◽  
Milk Clotting

scholarly journals Micellar electrokinetic chromatography after precapillary enzyme assay for the determination of phosphatase activity in semiarid soil

2009 ◽  
Vol 46 (2) ◽  
pp. 121-125 ◽  
Author(s):  
Patricia W. Stege ◽  
Germán A. Messina ◽  
Lorena L. Sombra ◽  
Guillermo Bianchi ◽  
Roberto A. Olsina
Keyword(s):  
Phosphatase Activity ◽  
Enzyme Assay ◽  
Micellar Electrokinetic Chromatography ◽  
Electrokinetic Chromatography

scholarly journals Spectrophotometric Determination of Glyoxylic Acid witho-Aminobenzaldehyde and Glycine, and Its Application to Enzyme Assay

1973 ◽  
Vol 37 (6) ◽  
pp. 1393-1400 ◽  
Author(s):  
Kenji Soda ◽  
Seizen Toyama ◽  
Haruo Misono ◽  
Toshiko Hirasawa ◽  
Kozi Asada
Keyword(s):  
Spectrophotometric Determination ◽  
Enzyme Assay ◽  
Glyoxylic Acid

Administration of a Mixture of Fungal Glucosidases to a Patient with Type II Glycogenosis (Pompe's Disease)

PEDIATRICS ◽  
1968 ◽  
Vol 42 (4) ◽  
pp. 672-676
Author(s):  
Ronald M. Lauer ◽  
Thelma Mascarinas ◽  
Antonio S. Racela ◽  
Antoni M. Diehl ◽  
Barbara Illingworth Brown
Keyword(s):  
Skeletal Muscle ◽  
Enzyme Assay ◽  
Glycogen Content ◽  
Hydrolytic Enzymes ◽  
Type Ii ◽  
Electron Microscopic ◽  
Pompe’S Disease ◽  
Pompe's Disease ◽  
Type Ii Glycogenosis

A case of Type II glycogenosis (Pompe's disease) has been studied by histochemical, electron microscopic, and biochemical techniques. These studies have been made prior to and after the intramuscular administration for 1 week of a mixture of hydrolytic enzymes containing both α-1,4- and α-1,6-glucosidase activities. Electron photomicrographs of the liver before enzyme administration showed glycogen to be located both within and outside of membrane-limited vacuoles. No change in this distribution could be detected in tissue removed by biopsy after enzyme administration. This impression was confirmed by the determination of glycogen content which was shown to be unchanged. Nevertheless, the liver was found by enzyme assay to contain the administered enzyme. Leucocytes isolated from blood taken 4 hours after the last enzyme injection were also shown to contain the parenterally administered glucosidases. In skeletal muscle glycogen was present chiefly as extrasaccular deposits which were unchanged in appearance by enzyme administration. No glucosidase activity was demonstrable in the skeletal muscle after such a treatment. Myocardium sectioned after autopsy had major deposits of glycogen in extrasaccular areas.

scholarly journals Amplification of Color Yield Obtained Using a Chromogenic Substrate for Determining Plasminogen Activator

1977 ◽  
Author(s):  
Robert B. Friedmaa ◽  
Hau C. Kwaan ◽  
Marija Szczecinski
Keyword(s):  
Absorption Maximum ◽  
Enzyme Assay ◽  
Amide Bond ◽  
Chromogenic Substrate ◽  
Present Communication ◽  
Red Color ◽  
Enzyme Digest ◽  
Color Yield ◽  
Ammonium Sulfamate

A synthetic chromogenic substrate has recently been reported for use in the specific measurement of urokinase. This material (Chromozym UK, marketed by Pentapharm, Ltd., Basle) is a synthetic tripeptide linked through an amide bond to the chromogen para-nitroaniline (PNA). The release of free PNA can be monitored spectrophotometrically by measuring the increase of absorbance of light in the range of 380 to 410 nm. The present communication describes our efforts at enhancing the color yield of the assay as well as changing the absorption maximum to a wavelength which can more readily and accurately be measured on inexpensive laboratory spectrophotometers .Bratton and Marshall have developed a method which can be used for the determination of aromatic amines in biological systems. We have modified this method for use in semimicro applications and have adapted it to the measurement of free PNA in solution. After acidification of an aliquot of the enzyme digest with trichloroacetic acid (TCA), the liberated PNA is diazotized with sodium nitrite. Excess nitrous acid is removed with ammonium sulfamate, and the diazotized PNA is reacted with 1-naphthylethylenediamine reagent. The product has a magenta-red color with an absorption maximum of 545 nm. The substrate is not affected by exposure to TCA, and when fresh reagents are used, a low background is obtained. The color yield during actual enzyme assay is amplified twenty fold. Other coupling agents are also currently under investigation.

scholarly journals The Relative Merits and Applicability of Kinetic and Fixed-Incubation Methods of Enzyme Assay in Clinical Enzymology

1972 ◽  
Vol 18 (12) ◽  
pp. 1449-1454 ◽  
Author(s):  
D W Moss
Keyword(s):  
Enzyme Activity ◽  
Continuous Monitoring ◽  
Enzyme Assay ◽  
Kinetic Method ◽  
Reaction Progress ◽  
Kinetic Principle ◽  
Clinical Enzymology

Abstract The considerations are discussed that make continuous monitoring of reaction-progress curves superior to fixed-incubation methods in the determination of enzyme activity. Provided that they are used with caution and their limitations are appreciated, fixed-incubation methods continue to fulfill a useful, though diminishing, role in clinical enzymology because of their adaptability to existing patterns of automation. The introduction of suitable mechanized equipment will favor the eventual complete adoption of the kinetic method. However, the use of such equipment should not be at the expense of th important characteristics of the kinetic principle.

Rapid enzymatic determination of urinary oxalate.

1989 ◽  
Vol 35 (12) ◽  
pp. 2330-2333 ◽  
Author(s):  
M G Li ◽  
M M Madappally
Keyword(s):  
Enzyme Assay ◽  
Divalent Cations ◽  
Urinary Oxalate ◽  
Assay Sensitivity ◽  
Color Development ◽  
Assay Procedure ◽  
Enzymatic Determination ◽  
Analytical Recovery ◽  
Urine Specimens

Abstract This new reagent kit for the quantitative measurement of oxalate in urine is a modification of an earlier Sigma oxalate assay procedure (procedure no. 590), a coupled enzyme assay involving oxalate oxidase and horseradish peroxidase. The new analytical procedure includes methods for processing urine specimens to eliminate interference with oxalate color development at 590 nm by ascorbic acid, divalent cations, and other urinary constituents. The reaction is complete in less than 5 min, and results are linearly related to oxalate concentration up to at least 1 mmol/L. Assay sensitivity and within-run and between-run precision were within the limits acceptable for other urinary oxalate procedures. Analytical recovery of added oxalate was close to 100%. This specific, simple, rapid procedure is suitable for routine clinical use.

Development of Radioimmunoassay for Gamma-Glutamyl Transferase Using Pancreatic Enzyme

1983 ◽  
Vol 20 (4) ◽  
pp. 247-250 ◽  
Author(s):  
Masanobu Masuike ◽  
Michio Ogawa ◽  
Takeshi Kitahara ◽  
Atsuo Murata ◽  
Kazuhiko Matsuda ◽  
...  
Keyword(s):  
Enzyme Assay ◽  
Pancreatic Enzyme ◽  
Gamma Glutamyl Transferase ◽  
Gamma Glutamyl ◽  
Standard Curve ◽  
Normal Individuals ◽  
The Mean ◽  
Glutamyl Transferase ◽  
Dilution Curves

A radioimmunoassay (RIA) for the determination of gamma-glutamyl transferase (GGT) was developed using human pancreatic enzyme as antigen. The assay allows the determination of GGT in concentrations as low as 80 ng/ml, and it is reproducible and specific. A good parallel relation was demonstrated between the standard curve and dilution curves for serum, urine, bile, and partially purified kidney GGT. In normal individuals, the mean serum concentration of GGT determined by RIA was found to be 3·43 μg/ml (SD ± 1·20). Enzyme activity calculated from the GGT concentration measured by the radioimmunoassay using a regression equation was approximately twice as great as that determined by conventional enzyme assay.

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