scholarly journals Milk xanthine oxidase type D (dehydrogenase) and type O (oxidase). Purification, interconversion and some properties

1973 ◽  
Vol 131 (2) ◽  
pp. 191-198 ◽  
Author(s):  
M. G. Battelli ◽  
E. Lorenzoni ◽  
F. Stirpe
Keyword(s):  
Xanthine Oxidase ◽  
Rat Liver ◽  
Gel Electrophoresis ◽  
Small Extent ◽  
Kinetic Constants ◽  
Cow’S Milk ◽  
Dihydrolipoic Acid ◽  
Cow's Milk ◽  
Type D ◽  
A Minor

1. The xanthine oxidase of cow's milk, crude or purified, appears as an oxidase (type O), and can be converted almost completely into a NAD+-dependent dehydrogenase (type D) by treatment with dithioerythritol or dihydrolipoic acid, but only to a small extent by other thiols. 2. The D form of the enzyme is inhibited by NADH, which competes with NAD+. 3. The kinetic constants of the two forms of the enzyme are similar to those of the corresponding forms of rat liver xanthine oxidase. 4. Milk xanthine oxidase is converted into an irreversible O form by pretreatment with chymotrypsin, papain or subtilisin, but only partially with trypsin. 5. The enzyme as purified shows a major faster band and a minor slower band on gel electrophoresis. The slower band is greatly reinforced after xanthine oxidase is converted into the irreversible O form by chymotrypsin.

Inhibition of Cow's Milk Xanthine Oxidase by Flavonoids

1988 ◽  
Vol 51 (2) ◽  
pp. 345-348 ◽  
Author(s):  
Toshimitsu Hayashi ◽  
Kazuko Sawa ◽  
Masaru Kawasaki ◽  
Munehisa Arisawa ◽  
Minen Shimizu ◽  
...  
Keyword(s):  
Xanthine Oxidase ◽  
Cow’S Milk ◽  
Cow's Milk

Detection of cow's milk in goat's milk by gel electrophoresis

1968 ◽  
Vol 35 (3) ◽  
pp. 383-384 ◽  
Author(s):  
R. Aschaffenburg ◽  
Janet E. Dance
Keyword(s):  
Gel Electrophoresis ◽  
Cow’S Milk ◽  
Cow's Milk ◽  
Goat’S Milk ◽  
Goat's Milk

Hypersensitivity to cow's milk is not uncommon in humans, particularly babies and infants. Those afflicted may be found to tolerate goat's milk which, in this country, commands a considerably higher price than cow's milk. For economic as well as ethical reasons it is therefore desirable to ascertain that goat's milk offered for sale is free from admixtures of cow's milk. Tests should be sensitive to relatively minor admixtures, since even small additions of cow's milk may undo the benefit which hypersensitive subjects expect to derive from the consumption of goat's milk.

scholarly journals Zinc binding in cow's milk and human milk

1983 ◽  
Vol 209 (2) ◽  
pp. 505-512 ◽  
Author(s):  
P Blakeborough ◽  
D N Salter ◽  
M I Gurr
Keyword(s):  
Molecular Weight ◽  
Human Milk ◽  
Average Molecular Weight ◽  
Human Infant ◽  
Zinc Binding ◽  
Cow’S Milk ◽  
Major Protein ◽  
Cow's Milk ◽  
Beta Casein ◽  
A Minor

In both cow's milk and human milk, zinc was associated with proteins of high molecular weight (greater than 100 000), as judged by analysis with Sephadex G-75. Precipitation of the casein at pH 4.6 and filtration of the resultant acid whey on Sephadex G-25 led, however, to the recovery of about 90% of the zinc as a compound of low molecular weight, which was tentatively identified as zinc citrate. Over 95% of the zinc of cow's milk was sedimented with the casein micelles on ultracentrifugation. Filtration of these micellar caseins on Sephadex G-150 gave two peaks containing zinc, which corresponded to aggregates of alpha-casein-kappa-casein and of alpha-casein-beta-casein. Ultracentrifugation of human milk sedimented only approx. 40% of total zinc. Analysis of sediment and supernatant on Sephadex G-150, however, indicated that about 85% of the zinc was associated with a protein complex of molecular weight greater than 150 000. The major protein of this complex was identified as lactoferrin. A minor zinc-binding component of average molecular weight 30 000 was also observed in the supernatant. The results indicated that zinc is bound to different macromolecules in cow's and human milk. This may be a factor affecting the bioavailability to the human infant of zinc from the two milks, and it is suggested that in human milk lactoferrin may be involved in the uptake of zinc.

A platelet aggregating substance contained in xanthine oxidase preparation from cow's milk

1982 ◽  
Vol 28 (1) ◽  
pp. 85-92 ◽  
Author(s):  
Hidemi Ishii ◽  
Sayuri Hiraishi ◽  
Mutsuyoshi Kazama
Keyword(s):  
Xanthine Oxidase ◽  
Cow’S Milk ◽  
Cow's Milk
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