scholarly journals The effect of antioxidants on xanthine oxidase activity in fresh ovine milk

10.5219/1662 ◽  
2021 ◽  
Vol 15 ◽  
pp. 599-607
Author(s):  
Akmaral Mukhamejanova ◽  
Zerekbay Alikulov ◽  
Nelya Shapekova ◽  
Karlygash Aubakirova ◽  
Abilkhas Mukhtarov
Keyword(s):  
Heat Treatment ◽  
Xanthine Oxidase ◽  
Active Center ◽  
Milk Fat ◽  
Natural Antioxidants ◽  
Effective Electron ◽  
Heated Milk ◽  
Milk Fat Globule ◽  
Enzyme Molecules ◽  
Nitrate And Nitrite

In the present, the consequences of nitrate pollution of the environment are very pronounced. In humans and animals, microorganisms can reduce nitrates to nitrites, which cause cancer. Purified and homogeneous xanthine oxidase (XO) of cow's milk can restore these compounds, which makes the article extremely relevant. The purpose of the article is to determine the effect of antioxidants on the activity of xanthine oxidase in fresh ovine milk. Various natural and artificial antioxidants were examined for the detection of xanthine oxidase (XO) activity in ovine milk. Among the natural antioxidants, L-cysteine was more effective in the stabilization of XO in heated milk. XO of sheep milk activated by heat treatment in the presence of cysteine and molybdenum became able to convert nitrate and nitrite to nitric oxide (NO). Therefore, L-cysteine was used for double purposes: as the protector of enzyme active center against the oxidation during heat treatment of milk and as a reagent for S-nitrosothiol formation. Hypoxanthine, as a natural substrate of XO, is an effective electron donor for nitrate reductase (NR) and nitrite reductase (NiR) activities. Heat treatment of the milk in the presence of exogenous lecithin increased the activity of NR and NiR of XO and CysNO formation. Thus, during the heat treatment: a) excess of exogenous phospholipids disintegrates the structure of milk fat globule membrane (MFGM) and b) enzyme molecules denatured partially and their active center became available for exogenous cysteine, molybdenum, hypoxanthine, and nitrate or nitrite.

The oxidation of lipids by components of bovine milk-fat globule membrane

1977 ◽  
Vol 44 (3) ◽  
pp. 495-507 ◽  
Author(s):  
J. C. Allen ◽  
Catherine Humphries
Keyword(s):  
Heat Treatment ◽  
Xanthine Oxidase ◽  
Isoelectric Focusing ◽  
Milk Fat ◽  
Oxidase Activity ◽  
Bovine Milk ◽  
Zwitterionic Surfactant ◽  
Milk Fat Globule Membrane ◽  
Milk Fat Globule ◽  
Fat Globule

SummaryBovine milk-fat globule membrane was solubilized with a zwitterionic surfactant and subjected to chromatography on agarose, with the surfactant in the eluant. Fractions were tested for their effects on the oxidation of buffered linoleate. The maximum oxidative capability was greatly enhanced by the addition of Cu, and became associated with the phospholipids.Further chromatography of the retarded protein peak from agarose on Sephadex G-200, again in the presence of surfactant, gave 2 protein peaks. Oxidative effectiveness resided almost entirely in the first peak, which was devoid of phospholipid, but high in xanthine oxidase activity. This fraction was subjected to isoelectric focusing, and the xanthine oxidase from this was highly pro-oxidative. Furthermore, its oxidative capability was almost doubled on heat treatment.

Chemical changes in bovine milk fat globule membrane caused by heat treatment and homogenization of whole milk

2002 ◽  
Vol 69 (4) ◽  
pp. 555-567 ◽  
Author(s):  
SUNG JE LEE ◽  
JOHN W. SHERBON
Keyword(s):  
Heat Treatment ◽  
Membrane Proteins ◽  
Milk Fat ◽  
Whey Proteins ◽  
Bovine Milk ◽  
Chemical Changes ◽  
Milk Fat Globule Membrane ◽  
Whole Milk ◽  
Milk Fat Globule ◽  
Fat Globule

The effects of heat treatment and homogenization of whole milk on chemical changes in the milk fat globule membrane (MFGM) were investigated. Heating at 80 °C for 3–18 min caused an incorporation of whey proteins, especially β-lactoglobulin (β-lg), into MFGM, thus increasing the protein content of the membrane and decreasing the lipid. SDS-PAGE showed that membrane glycoproteins, such as PAS-6 and PAS-7, had disappeared or were weakly stained in the gel due to heating of the milk. Heating also decreased free sulphydryl (SH) groups in the MFGM and increased disulphide (SS) groups, suggesting that incorporation of β-lg might be due to association with membrane proteins via disulphide bonds. In contrast, homogenization caused an adsorption of caseins to the MFGM but no binding of whey proteins to the MFGM without heating. Binding of caseins and whey proteins and loss of membrane proteins were not significantly different between milk samples that were homogenized before and after heating. Viscosity of whole milk was increased when milk was treated with both homogenization and heating.

Glycoprotein Filament Removal From Human Milk Fat Globules by Heat Treatment

PEDIATRICS ◽  
1988 ◽  
Vol 81 (1) ◽  
pp. 141-146
Author(s):  
Wolfgang Buchheim ◽  
Ulrich Welsch ◽  
Gail E. Huston ◽  
Stuart Patton
Keyword(s):  
Milk Fat ◽  
Electrophoretic Analysis ◽  
Fat Absorption ◽  
Fat Globules ◽  
Heated Milk ◽  
Milk Fat Globules ◽  
Milk Fat Globule ◽  
Fat Globule ◽  
Human Milk Fat ◽  
Additional Explanation

Freeze-etch electron microscopy was applied to milk fat globules to observe surface details. A remarkable array of filaments, approximately 0.5 µm in length, was seen on human, but not bovine, globules. Heating human globules removed the filaments that were identified as high molecular weight glycoproteins by freezeetch and gel electrophoretic analysis of the heating medium. Extraction of these globule glycoproteins was slight at 60°C for one minute but substantial and tending to plateau at 80°C for one minute. Such heat-induced alterations of the milk fat globule surface provide an alternative or additional explanation to milk lipase inactivation as the cause of reduced milk fat absorption from heated milk by the preterm infant.

scholarly journals Preparation of monoclonal antibodies to xanthine oxidase and other proteins of bovine milk-fat-globule membrane

1980 ◽  
Vol 188 (3) ◽  
pp. 925-928 ◽  
Author(s):  
I H Mather ◽  
C S Nace ◽  
V G Johnson ◽  
R A Goldsby
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Xanthine Oxidase ◽  
Cell Lines ◽  
Milk Fat ◽  
Bovine Milk ◽  
Serial Transfer ◽  
Milk Fat Globule Membrane ◽  
Milk Fat Globule ◽  
Fat Globule

Nine hybridomas secreting monoclonal antibody to proteins of bovine milk-fat-globule membrane were isolated. All nine cell lines continued to secrete monoclonal antibody after serial transfer in culture and after passage as solid tumours in Balb/cJ mice. Four of the cell lines secreted monoclonal antibody specific for xanthine oxidase, one of the major proteins of milk-fat-globule membrane.

Effects of mono‐ and diglycerides of fatty acids on the milk fat globule membrane after heat treatment

2020 ◽  
Vol 73 (4) ◽  
pp. 667-673
Author(s):  
Dima Atehli ◽  
Jianming Wang ◽  
Jinghua Yu ◽  
Fatma Ali ◽  
Yi Wang
Keyword(s):  
Heat Treatment ◽  
Fatty Acids ◽  
Milk Fat ◽  
Milk Fat Globule Membrane ◽  
Milk Fat Globule ◽  
Fat Globule

scholarly journals Association of xanthine oxidase with the bovine milk-fat-globule membrane. Nature of the enzyme-membrane association.

1975 ◽  
Vol 147 (3) ◽  
pp. 417-423 ◽  
Author(s):  
M S Briley ◽  
R Eisenthal
Keyword(s):  
Xanthine Oxidase ◽  
Milk Fat ◽  
Oxidase Activity ◽  
Bovine Milk ◽  
Membrane Association ◽  
Milk Fat Globule Membrane ◽  
Xanthine Oxidase Activity ◽  
Milk Fat Globule ◽  
Fat Globule ◽  
Triton X

1. Xanthine oxidase (EC 1.2.3.2) was found to represent more than 8% of the intrinsic protein of the bovine milk-fat-globule membranes. 2. Less than 25% of the xanthine oxidase activity of the fat-globule membrane was solubilized with 0.1 M-sodium pyrophosphate buffer or 2M-NaCl. Of the particulate activity remaining 56% was solubilized with Triton X-100. 3. The xanthine oxidase activity solubilized with buffer, 2M-NaCl or Triton X-100 was not liberated as the free enzyme. Only tryptic digestion was found to release the free enzyme from the fat-globule membrane. Tryptic digestion also liberated free xanthine oxidase from those fractions solubilized by buffer or NaCl, but not from those fractions solubilized with Triton X-100 or by sonication. 4. The effect of membrane association on the catalytic properties of the enzyme could be mimicked by low pH or by the presence in the assay mixture of certain concentrations of 2-methyl-propan-2-ol, but not 1,4-dioxan, suggesting that hydrogen-bonding rather than low dielectric constant may be involved. 5. The origin of the milk-fat-globule membrane is discussed with reference to the intrinsic nature of the associated xanthine oxidase activity.

The use of marker enzymes to assay the churning of milk

1975 ◽  
Vol 42 (2) ◽  
pp. 241-246 ◽  
Author(s):  
D. J. Stannard
Keyword(s):  
Alkaline Phosphatase ◽  
Xanthine Oxidase ◽  
Milk Fat ◽  
Marker Enzymes ◽  
Milk Fat Globule Membrane ◽  
Factors Affecting ◽  
Assay Procedure ◽  
Milk Fat Globule ◽  
Fat Globule

SummaryThe release of the enzymes xanthine oxidase and alkaline phosphatase from the milk fat globule membrane is shown to be an index of milk churning. The factors affecting globule breakdown in relation to this assay procedure are discussed.

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