Standardization of Serum Ceruloplasmin Concentrations in International Enzyme Units with o-Dianisidine Dihydrochloride as Substrate

1974 ◽  
Vol 20 (12) ◽  
pp. 1564-1567 ◽  
Author(s):  
H Peter Lehmann ◽  
Karl H Schosinsky ◽  
Myrton F Beeler
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidase Activity ◽  
Serum Ceruloplasmin

Abstract We describe a method for calculating the absorptivity (in terms of substrate consumed) of the colored solution obtained when o-dianisidine dihydrochloride is oxidized by ceruloplasmin. By oxidizing o-dianisidine dihydrochloride with known amounts of hydrogen peroxide we could determine that the molar reacting ratio of o-dianisidine to hydrogen peroxide is 2:1. So calculated, absorptivity is 9.6 ml µmol-1 cm-1, the figure used to estimate ceruloplasmin oxidase activity in terms of International Units.

Impairment of Platelet Aggregation by Echis colorata Venom Mediated by L-Amino Acid Oxidase or H2O2

1982 ◽  
Vol 48 (03) ◽  
pp. 277-282 ◽  
Author(s):  
I Nathan ◽  
A Dvilansky ◽  
T Yirmiyahu ◽  
M Aharon ◽  
A Livne
Keyword(s):  
Hydrogen Peroxide ◽  
Amino Acid ◽  
Platelet Aggregation ◽  
Snake Venom ◽  
Oxidase Activity ◽  
Enzyme Preparation ◽  
Acid Oxidase ◽  
Crude Venom ◽  
Amino Acid Oxidase ◽  
Hemostatic Disorders

SummaryEchis colorata bites cause impairment of platelet aggregation and hemostatic disorders. The mechanism by which the snake venom inhibits platelet aggregation was studied. Upon fractionation, aggregation impairment activity and L-amino acid oxidase activity were similarly separated from the crude venom, unlike other venom enzymes. Preparations of L-amino acid oxidase from E.colorata and from Crotalus adamanteus replaced effectively the crude E.colorata venom in impairment of platelet aggregation. Furthermore, different treatments known to inhibit L-amino acid oxidase reduced in parallel the oxidase activity and the impairment potency of both the venom and the enzyme preparation. H2O2 mimicked characteristically the impairment effects of L-amino acid oxidase and the venom. Catalase completely abolished the impairment effects of the enzyme and the venom. It is concluded that hydrogen peroxide formed by the venom L-amino acid oxidase plays a role in affecting platelet aggregation and thus could contribute to the extended bleeding typical to persons bitten by E.colorata.

Serum ceruloplasmin oxidase activity is a specific and non-invasive marker for Wilson disease

2008 ◽  
Vol 46 (01) ◽  
Author(s):  
U Merle ◽  
C Eisenbach ◽  
KH Weiss ◽  
S Tuma ◽  
W Stremmel
Keyword(s):  
Wilson Disease ◽  
Oxidase Activity ◽  
Serum Ceruloplasmin ◽  
Non Invasive

THE OXIDATION OF ESTRONE-16-C14BY PEROXIDASE

1962 ◽  
Vol 40 (1) ◽  
pp. 459-469 ◽  
Author(s):  
P. H. Jellinck ◽  
Louise Irwin
Keyword(s):  
Amino Acids ◽  
Hydrogen Peroxide ◽  
Amino Acid ◽  
Serum Albumin ◽  
Oxidase Activity ◽  
Water Soluble ◽  
The Other ◽  
Aerobic Incubation ◽  
Nitrogenous Compounds ◽  
Initial Generation

Aerobic incubation of estrone-16-C14with peroxidase in the presence of serum albumin and other proteins resulted in the formation of water-soluble, ether-insoluble metabolites in high percentage yields. Similar products were formed when protein was replaced by cysteine or tryptophan but none of the other amino acids tested had any effect. The evidence points to an initial generation of hydrogen peroxide from these nitrogenous compounds by the enzyme acting as an aerobic oxidase, and the subsequent peroxidation of estrone to highly reactive products. These then combine with the protein or amino acid or else undergo alternative reactions. A strong chemical bond is formed with albumin and attempts to release the estrone metabolites from it were unsuccessful. Uterine homogenates from estrogen-treated rats showing high DPNH oxidase activity contained no "peroxidase" as measured by the formation of water-soluble products from estrone in the presence of protein.

Effects of some oxidants and antioxidants on senescence of isolated leaves of sunflower with special reference to glycolate content, glycolate oxidase, and catalase activities

1981 ◽  
Vol 59 (3) ◽  
pp. 392-396 ◽  
Author(s):  
Udayan Sarkar ◽  
M. A. Choudhuri
Keyword(s):  
Hydrogen Peroxide ◽  
Special Reference ◽  
Helianthus Annuus ◽  
Oxidase Activity ◽  
Glycolate Oxidase ◽  
Leaf Discs ◽  
Helianthus Annuus L ◽  
Protein Levels ◽  
General Decline ◽  
Chlorophyll Protein

Incubation of leaf discs of sunflower (Helianthus annuus L. cv. EC.68414) for 6 days in the dark caused a general decline in the contents of chlorophyll, protein, and glycolate in these tissues as well as in the activities of catalase and glycolate oxidase. Treatments with either glycolate or hydrogen peroxide decreased the contents of chlorophyll and protein and the activity of catalase but increased glycolate oxidase activity, hastening senescence. Treatments with ascorbate or 2-mercaptoethanol significantly arrested the decline in chlorophyll and protein levels, deferring senescence. Glycolate content was reduced in leaves treated with glycolate, hydrogen peroxide, ascorbate, or 2-mercaptoethanol. But the extent of reduction in the latter case was less pronounced than that following treatments with glycolate or hydrogen peroxide. Only the highest concentrations of either ascorbate or 2-mercaptoethanol increased the activity of catalase, whereas glycolate oxidase activity was increased by these chemicals in all concentrations.

Elimination of the "chromogen oxidase" activity of bilirubin oxidase added to obviate bilirubin interference in hydrogen peroxide/peroxidase detecting systems.

1985 ◽  
Vol 31 (12) ◽  
pp. 2007-2008 ◽  
Author(s):  
G A Maguire
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidase Activity ◽  
Bilirubin Oxidase ◽  
Sequential Addition

Abstract The use of bilirubin oxidase to remove interference by bilirubin in hydrogen peroxide/peroxidase detecting systems is hampered by its inherent "chromogen oxidase" activity (its ability to oxidize the chromogens used in the systems). This unwanted activity is greater than 99% inhibited by 0.5 mmol/L cyanide, 97% inhibited by 20 mmol/L azide. At these same concentrations, they inhibit bilirubin oxidase activity by 95% and 73%, respectively. Sequential addition of reagents allows the use of bilirubin oxidase without interference by the chromogen oxidase activity.

Measurement of Ceruloplasmin from Its Oxidase Activity in Serum by Use of o-Dianisidine Dihydrochloride

1974 ◽  
Vol 20 (12) ◽  
pp. 1556-1563 ◽  
Author(s):  
Karl H Schosinsky ◽  
H Peter Lehmann ◽  
Myrton F Beeler
Keyword(s):  
Coefficient Of Variation ◽  
Oxidase Activity ◽  
New Method ◽  
Radial Immunodiffusion ◽  
Normal Range ◽  
Serum Ceruloplasmin ◽  
Stable Product ◽  
Method R

Abstract We have developed a new method for determination of serum ceruloplasmin from its oxidase activity, in which o-dianisidine dihydrochloride is used as substrate. o-Dianisidine dihydrochloride is more stable than is the more widely used p-phenylenediamine substrate, and forms a stable product that is measured at 540 nm. Correlation was good between results of this method and those obtained with both a p-phenylenediamine substrate method (r = 0.98) and a radial immunodiffusion procedure (r = 0.97). There is little or no interference from reducing or colored components of serum. The coefficient of variation (day-to-day) for the method was 4.2%. A normal range of 62-140 U/ liter has been determined by the reported method.

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