A Study of the Colorimetric Dinitrophenylhydrazine Method for the Determination of Serum Glutamic Oxalacetic Transaminase Activity

1966 ◽  
Vol 12 (4) ◽  
pp. 217-225 ◽  
Author(s):  
J S Annino
Keyword(s):  
Enzyme Activity ◽  
Transaminase Activity ◽  
Reagent Blank ◽  
Glutamic Oxalacetic Transaminase ◽  
Color Development ◽  
High Enzyme ◽  
Serum Glutamic Oxalacetic Transaminase ◽  
The Relationship ◽  
High Enzyme Activity

Abstract Study of the colorimetric transaminase method of Reitman and Frankel for the determination of serum glutamic oxalacetic transaminase activity revealed the following: (1) although maximum absorption occurs at 444 mµ, absorbance readings at 505 mµ gave satisfactory results; (2) color development is immediate and the color is stable for at least 1 hr.; (3) a pyruvate calibration standard may be used; (4) sample blanks are not usually necessary; (5) a reagent blank should accompany each group of analyses and should be used as a photometric reference; (6) the relationship between dilution and enzyme activity is linear; and (7) although the relationship between incubation time and activity is not exactly linear, a factor has been determined to permit the use of a 12-min. incubation period with samples showing high enzyme activity.

Determination of Glutamic Oxalacetic Transaminase Activity by Coupling of Oxalacetate with Diazonium Salts

1967 ◽  
Vol 13 (3) ◽  
pp. 175-185 ◽  
Author(s):  
Sylvan M Sax ◽  
John J Moore
Keyword(s):  
Spectrophotometric Method ◽  
Diazonium Salt ◽  
Diazonium Salts ◽  
Transaminase Activity ◽  
Linear Rate ◽  
Glutamic Oxalacetic Transaminase ◽  
Serum Glutamic Oxalacetic Transaminase ◽  
Substrate Concentrations ◽  
Colorimetric Methods

Abstract A method for measuring serum glutamic oxalacetic transaminase activity is described, in which substrate concentrations are more nearly optimal than in previous colorimetric methods. By coupling the diazonium salt at a pH of 4.2, interference from α-oxoglutarate is negligible. Oxalacetate is produced at a linear rate to 180 I.U. Results correlate well with those obtained by a reference spectrophotometric method.

scholarly journals A method for determining kinetic parameters at high enzyme concentrations

1982 ◽  
Vol 203 (1) ◽  
pp. 339-342 ◽  
Author(s):  
C J Halfman ◽  
F Marcus
Keyword(s):  
Enzyme Activity ◽  
Kinetic Parameters ◽  
Graphical Method ◽  
Free Ligand ◽  
Enzyme Concentration ◽  
Fructose 1,6 Bisphosphatase ◽  
High Enzyme ◽  
Substrate Inhibitor ◽  
The Relationship

A graphical method is described which allows determination of kinetic parameters when substrate, inhibitor or activator concentrations must be in the vicinity of the enzyme concentration and a significant fraction of ligand is bound. Velocity is measured at several ligand: enzyme ratios at two or more enzyme concentrations. Results are obtained in terms of free and bound ligand corresponding to particular velocities. The relationship between velocity and bound and free ligand may then be analysed by any desired plotting technique. Preknowledge of the reaction mechanism or experimental determination of Vmax. is not required. The relationship between ligand bound and enzyme activity need not be linear and the method is equally suitable for analysing co-operative as well as simple kinetics. Application of the method is demonstrated by analysis of the inhibition of fructose, 1,6-bisphosphatase by AMP.

Electrophoretic Migration Pattern of Serum Glutamic Oxalacetic Transaminase

1958 ◽  
Vol 4 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Herndon G Shepherd ◽  
Hugh J McDonald
Keyword(s):  
Pyridoxal Phosphate ◽  
Serum Proteins ◽  
Migration Pattern ◽  
Globulin Fraction ◽  
Transaminase Activity ◽  
Rat Serum ◽  
Glutamic Oxalacetic Transaminase ◽  
Electrophoretic Migration ◽  
Serum Glutamic Oxalacetic Transaminase

Abstract Using the combined technics of the ionographic separation of serum proteins in a paper-stabilized medium, as described by McDonald et al. (16, 17, 18), and the spectrophotometric procedure for the determination of transaminase activity developed by Karmen (3, 14), the electrophoretic migration pattern of the enzyme glutamic oxalacetic transaminase in rat serum has been examined. The major portion of the transaminase activity has been found to be associated with the α-2 globulin fraction of the serum proteins. Further evidence has been presented for the assumption of a nonionic linkage between the enzyme and its coenzyme, pyridoxal phosphate.

Su1843 High Enzyme Activity UGT1A1 or Low Activity Ugt1a8 and Ugt2b4 Genotypes Increase Esophageal Cancer Risk

2012 ◽  
Vol 142 (5) ◽  
pp. S-517
Author(s):  
Polat Dura ◽  
Jody Salomon ◽  
Rene te Morsche ◽  
Hennie Roelofs ◽  
Jon Kristinsson ◽  
...  
Keyword(s):  
Esophageal Cancer ◽  
Enzyme Activity ◽  
Cancer Risk ◽  
High Enzyme ◽  
Low Activity ◽  
High Enzyme Activity

Internodal invertases and stalk maturity in sugarcane

1991 ◽  
Vol 116 (2) ◽  
pp. 239-243 ◽  
Author(s):  
H. L. Sehtiya ◽  
J. P. S. Dendsay ◽  
A. K. Dhawan
Keyword(s):  
Enzyme Activity ◽  
Cell Expansion ◽  
Reducing Sugars ◽  
Sucrose Solution ◽  
Invertase Activity ◽  
Neutral Invertase ◽  
High Enzyme ◽  
Stem Slices ◽  
High Enzyme Activity

SUMMARYAcid and neutral invertase activities in the stem of an early (CoJ 64) and a late cultivar (Col 148) of sugarcane were estimated by incubating stem slices in buffered sucrose solution and measuring the production of reducing sugars. High enzyme activity occurred in young tissue but the activity of both enzymes was considerably lower in the mature internodes. Acid and neutral invertase activity was highest in the midinternode position, corresponding to the region of cell expansion.

Preparation of enzymatically highly active pegylated-D-amino acid oxidase and its application to antitumor therapy

2021 ◽  
Vol 18 ◽  
Author(s):  
Hideaki Nakamura ◽  
Appiah Enoch ◽  
Shotaro Iwaya ◽  
Sakura Furusho ◽  
Shoko Tsunoda ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Antitumor Effect ◽  
Tumor Tissue ◽  
Acid Oxidase ◽  
Antitumor Therapy ◽  
Amino Acid Oxidase ◽  
Tumor Bearing ◽  
Highly Active ◽  
High Enzyme ◽  
High Enzyme Activity

Background: D-amino acid oxidase (DAO) is an H2O2-generating enzyme, and tumor growth suppression by selective delivery of porcine DAO in tumors via the cytotoxic action of H2O2 has been reported. DAO isolated from Fusarium spp. (fDAO) shows much higher enzyme activity than porcine DAO, although the application of fDAO for antitumor treatment has not yet been determined. Objective: The purpose of this study was to prepare enzymatically highly active pegylated-fDAO, and to determine whether it accumulates in tumors and exerts a potent antitumor effect in tumor-bearing mice. Methods: Polyethylene glycol (PEG; Mw. 2000) was conjugated to fDAO to form PEGylated fDAO (PEG-fDAO). PEGfDAO was intravenously administered into S180 tumor-bearing mice, and the body distribution and antitumor activity of PEG-fDAO was determined. Results: The enzyme activity of PEG-fDAO was 26.1 U/mg, which was comparable to that of fDAO. Intravenously administered PEG-fDAO accumulated in tumors with less distribution in normal tissue except in the plasma. Enzyme activity in the tumor was 60–120 mU/g-tissue over 7–20 h after i.v. injection of 0.1 mg of PEG-fDAO. To generate the H2O2 in the tumor tissue, PEG-fDAO was intravenously administered, and then, D-phenylalanine was intraperitoneally administered after a lag time. No remarkable tumor suppression effect was observed under conditions used in this study, compared to the non-treated group. Conclusion: The results suggest that PEG-fDAO maintained high enzymatic activity after pegylation. Treatment with PEGfDAO conferred high enzyme activity on tumor tissue; 3–6 fold higher than that of previously reported pDAO; however, high enzyme activity in the plasma limited repeated treatment owing to lethal toxicity, which seemingly led to poor therapeutic outcome. Overall, the use of PEG-fDAO is promising for antitumor therapy, although the suppression of DAO activity in the plasma would also be required rather than only the increase in DAO activity in the tumor for an antitumor effect.

Sources of Variation in a Standardized and a Semi-micro Procedure for the Spectrophotometric Assay of Serum Glutamic-Oxalacetic Transaminase Concentration

1958 ◽  
Vol 4 (5) ◽  
pp. 392-408 ◽  
Author(s):  
A J Schneider ◽  
Myron J Willis
Keyword(s):  
Arrhenius Equation ◽  
Spectrophotometric Assay ◽  
Light Path ◽  
Transaminase Activity ◽  
Arrhenius Law ◽  
Glutamic Oxalacetic Transaminase ◽  
Sources Of Variation ◽  
The Mean ◽  
Serum Glutamic Oxalacetic Transaminase ◽  
Temperature Factors

Abstract 1. Both a standard method and a semi-micro method for the spectrophotometric assay of serum glutamic-oxalacetic transaminase (S-GOT) concentrations have been described. 2. Either procedure is associated with an error defined by a factor of less than 1.03. 3. The temperature dependence of the rate of transamination was shown to follow Arrhenius' law over the range of temperature from 25° to 38°. 4. A tabulation of temperature factors calculated from the derived Arrhenius equation was presented. These factors permit correction of rates observed at temperature T to rates expected at 32°. 5. A comparison of normal S-GOT values from various sources was made, with correction for temperature differences. Based on 779 values from four different laboratories, the combined mean for adults was 21.9. 6. A standard unit of transaminase activity was defined and referred to as a Karmen unit. A Karmen unit represents that amount of transaminase in 1 ml. of sample which will cause a decrease in optical density at 340 mµ of 0.001 per minute at a temperature of 32°, an effective light path of 1 cm., and a volume of test solution of 3 ml. According to this definition, the mean normal adult S-GOT concentration is 21.9 Karmen units. The practical upper limit of normal will be defined in another publication.

Adaptation of Babson's Method for the Determination of Serum Glutamic Oxalacetic Transaminase in the Clinical Laboratory

1965 ◽  
Vol 11 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Masaki Furuno ◽  
Albert Sheena
Keyword(s):  
Clinical Laboratory ◽  
Glutamic Oxalacetic Transaminase ◽  
Laboratory Workers ◽  
Routine Clinical Laboratory ◽  
Serum Glutamic Oxalacetic Transaminase ◽  
Final Color

Abstract Babson's method for the assay of serum glutamic oxalacetic transaminase (SGO-T) is modified to increase its accuracy and reliability. The final color produced is made stable with the addition of bisulfite ion, thereby making the procedure more suitable for the routine clinical laboratory. The 95% limits for values on 20 healthy laboratory workers was 4 to 26 units with a mean of 13 units.

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