Determination of malolactic enzyme activity using an immobilized L-lactate oxidase probe

1991 ◽  
Vol 5 (5) ◽  
Author(s):  
J.M. Salmon
1966 ◽  
Vol 12 (5) ◽  
pp. 308-313 ◽  
Author(s):  
Albert W Opher ◽  
Charles S Collier ◽  
Joseph M Miller

Abstract A convenient electrophoretic procedure for the separation and quantitation of lactate dehydrogenase (LDH) isoenzymes is described. The system uses polyacetate Sepraphore III strips.* The areas of activity are shown by incubation with an LDH substrate combined with tetra-nitro-blue-tetrazolium. The reduction of the latter to the purple formazan is quantitatively related to the enzyme activity. Quantitative determination of the individual colored areas is performed by densitometry.


1990 ◽  
Vol 11 (3-4) ◽  
pp. 213-218 ◽  
Author(s):  
P. Chagnaud ◽  
P. Naouri ◽  
A. Arnaud ◽  
P. Galzy

1966 ◽  
Vol 12 (4) ◽  
pp. 217-225 ◽  
Author(s):  
J S Annino

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.


1980 ◽  
Vol 35 (3-4) ◽  
pp. 209-212 ◽  
Author(s):  
B. Schöbel ◽  
W. Pollmann

Abstract The isolation and characterization of a specific chlorogenic acid esterase is described. The enzyme activity is measured by determination of the hydrolysis product caffeic acid. The enzyme had been concentrated by means of ultrafiltration and column-chromatography. The pH- and temperature optimum were 6.5 and 45 °C respectively. Divalent cations were not required for the enzyme activity. As other esterases, this enzyme is inhibited by di-isopropyl-phosphorofluoridate. The Km-value is 0.70 mᴍ chlorogenic acid, the molecular weight 240000. The described enzyme is specific for chlorogenic acid. On the other hand a typical unspecific esterase like the pig liver esterases does not split chloro­genic acid. The isoelectric focusing reveals several isoenzymes of chlorogenase within a pI-range of 4.0-4.5.


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