scholarly journals Oxidative Modification of the Proteins of Breast and Cow Milk

2021 ◽  
Author(s):  
Valeriy E. Vysokogorskiy ◽  
Mariya A. Sokolova ◽  
Natalya V. Strelchik ◽  
Oksana N. Lazareva ◽  
Oleg V. Antonov
Keyword(s):  
Amino Acid ◽  
Breast Milk ◽  
Antioxidant Properties ◽  
Oxidative Modification ◽  
Cow Milk ◽  
Amino Acid Residues ◽  
Carbonyl Derivatives ◽  
Metal Catalyzed ◽  
Derivatives Of

One of the important modern characteristics of the nutritional and biological value of milk and dairy products is the antioxidant properties. The high stability and sensitivity of the determination of carbonyl derivatives of proteins, as well as the informative value of the action of antioxidants, allow using them as the markers of oxidative damage. The purpose of this paper was to compare the level of carbonyl derivatives of proteins in breast and cow milk. The determination of the oxidative modification of proteins was based on the reaction of carbonyl derivatives of amino acid residues with 2, 4-dinitrophenylhydrazine. The content of the products was determined during spontaneous and metal-catalyzed oxidative modification of the proteins. During the determination of the spontaneously formed carbonyl derivatives of the proteins, their significantly higher content in cow milk compared to breast milk was established. This increase ranged from 46% to 83% at different wavelengths. Thus, the determination of carbonyl derivatives of amino acid residues of the proteins made it possible to reveal significant differences in the antioxidant properties of breast and cow milk, manifested in a lower level of carbonyl derivatives in breast milk. The lower level of carbonyl derivatives in the composition of breast milk proteins is likely associated with the increased activity of the antioxidant system of breast milk or the increased rate of removal of damaged proteins upon activation of milk proteases. Keywords: carbonyl derivatives, oxidative modification, proteins, human milk, breast milk, metal-catalyzed

scholarly journals The influence of metals of variable valence on the oxidative modification of albumin amino acid residues

2021 ◽  
Vol 9 (3) ◽  
pp. 369-376
Author(s):  
O.A. Zav’yalova ◽  
◽  
Yu.A. Marsyanova ◽  
Yu.V. Abalenikhinа ◽  
A.F. Ishtulin ◽  
...  
Keyword(s):  
Amino Acid ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Mixed Valence ◽  
Oxidative Modification ◽  
Amino Acid Residues ◽  
Variable Valence ◽  
Carbonyl Derivatives ◽  
Derivatives Of

BACKGROUND: The constancy of the protein composition of the body is one of the most important conditions for normal vital activity. Deviations in the content of the main bioelements, in particular, mixed valence metals, caused by environmental factors, improper nutrition and other factors, lead to various disorders. One of the properties of metals of mixed valence is the abil-ity to cause metal-catalyzed oxidation of proteins in joint action with active forms of oxygen. It seems interesting to study the oxidative modification of the amino acid residues of albumin and the change in its properties. AIM: To study the effect of reactive oxygen intermediates generated by the Fenton reaction in the presence of Fe2+ and Cu2+ on the oxidative modification of amino acid residues of bovine serum albumin. MATERIALS AND METHODS: The study was carried out on bovine serum albumin (BSA), which was incubated for 2 hours in a mixture of Fenton's reagents – FeSO4 + H2O2 and in a mixture of СuSO4 + H2O2. The quantitative protein content in the samples was determined with the bromcresol green reagent (Albumin-Olvex). The content of carbonyl derivatives of proteins was estimated by the method of R.L. Levine modified by E.E. Dubinina. The content of thiol groups in albumin samples from the control and experimental groups was determined by the Ellman method with DTNB (under non-denaturing conditions. RESULTS: The presented results demonstrate that under the action of Cu2+ ions, the formation of carbonyl derivatives of aliphatic amino acids of albumin is less than in the presence of Fe2+, which can be explained by the different degrees of albumin affinity to metals of variable valence. The rate of mobility of oxidatively modified albumin in polyacrylamide gel decreases, which is explained by protein aggregation due to bityrosine cross-links. CONCLUSION: Variable valence metals affect the modification of albumin. The change in the functional properties of the protein is of physiological significance, including the case of extracellular mobilization of iron and copper.

Determination of the Complete Absolute Configuration of Petriellin A

2006 ◽  
Vol 59 (6) ◽  
pp. 407 ◽  
Author(s):  
Luigi Aurelio ◽  
Robert T. C. Brownlee ◽  
Jason Dang ◽  
Andrew B. Hughes ◽  
Gideon M. Polya
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Natural Product ◽  
Absolute Configuration ◽  
Structural Determination ◽  
Amino Acid Residues ◽  
The Common ◽  
The Absolute ◽  
Derivatives Of

We report the full structural determination of the depsipeptide petriellin A. The absolute configuration of the amino acid residues, N-methyl isoleucine and N-methyl threonine, have been determined by a combination of HPLC and TLC comparison of synthetic Marfey’s derivatives and Marfey’s derivatives of the natural product hydrolysate. The configuration of the chiral centres in these two N-methylated residues was found to be the same as those of the common unmethylated l-amino acids.

scholarly journals Age-related features of activity of free radical oxidation in erythrocyte membranes and blood plasma in postinfarction cardiosclerosis in rats

2018 ◽  
Vol 99 (4) ◽  
pp. 629-634
Author(s):  
T Yu Rebrova ◽  
S A Afanas’ev
Keyword(s):  
Amino Acid ◽  
Blood Plasma ◽  
Thiobarbituric Acid ◽  
Erythrocyte Membranes ◽  
Amino Acid Residues ◽  
Protein Amino Acid ◽  
Postinfarction Cardiosclerosis ◽  
Carbonyl Derivatives ◽  
Derivatives Of ◽  
In Blood Plasma

Aim. To determine the presence of lipid and protein peroxidation products in erythrocyte membranes and blood plasma in rats of different ages in an intact state and with developed postinfarction cardiosclerosis. Methods. In rats aged 4, 12, 24 months postinfarction cardiosclerosis was modeled by coronary occlusion. In blood plasma and erythrocyte membranes, products reacting with thiobarbituric acid and carbonyl derivatives of protein amino acid residues were determined. Results. In erythrocyte membranes of intact animals aged 12 months, a decrease of the content of thiobarbituric acid-reacting products was revealed in comparison with 4 month-old animals, and in 24 months-old animals the index significantly exceeded the values of young subjects. In the blood plasma of intact animals aged 12 and 24 months, an increased content of thiobarbituric acid-reacting products with respect to rats aged 4 months was revealed. In postinfarction cardiosclerosis, an increase in the accumulation of thiobarbituric acid-reacting products was observed in erythrocyte membranes of 4 and 24 months-old animals. In blood plasma, an increase of this parameter was noted only in the group of 4 months-old animals with postinfarction cardiosclerosis. In erythrocyte membranes of intact rats of all age groups, no differences in the level of carbonyl derivatives of protein amino acid residues were observed, and in blood plasma it significantly increased with age. In 4 and 12 months-old animals with postinfarction cardiosclerosis, significant increase of carbonyl derivatives of protein amino acid residues was mostly pronounced in erythrocyte membranes. In 24 months-old animals with postinfarction cardiosclerosis, this parameter in the membranes and blood plasma was stable. Conclusion. The intensity of processes of cell membrane and blood lipid peroxidation has pronounced age-dependent features that persist in postinfarction cardiosclerosis; proteins of erythrocyte membranes of intact animals are subject to peroxide modification to a lesser degree than blood plasma proteins; in postinfarction cardiosclerosis formation in 4 and 12 months-old animals, carbonyl derivatives of protein amino acid residues are more intensively accumulated in erythrocyte membranes compared to blood plasma.

Determination of Amino Acid Residues Responsible for Specific Interaction of Protein Kinases with Small Molecule Inhibitors

2018 ◽  
Vol 52 (3) ◽  
pp. 478-487 ◽  
Author(s):  
D. A. Karasev ◽  
A. V. Veselovsky ◽  
A. A. Lagunin ◽  
D. A. Filimonov ◽  
B. N. Sobolev
Keyword(s):  
Amino Acid ◽  
Protein Kinases ◽  
Small Molecule ◽  
Small Molecule Inhibitors ◽  
Specific Interaction ◽  
Amino Acid Residues

scholarly journals Synthesis and Evaluation of Cyclic Acetals of Serine Hydroxylamine for Amide-Forming KAHA Ligations

Synthesis ◽  
2019 ◽  
Vol 51 (05) ◽  
pp. 1273-1283 ◽  
Author(s):  
Simon Baldauf ◽  
Jeffrey Bode
Keyword(s):  
Amino Acid ◽  
Amino Acid Residue ◽  
Amino Acid Residues ◽  
High Demand ◽  
Cyclic Acetals ◽  
Ligation Product ◽  
Canonical Amino Acid ◽  
The Stability ◽  
Peptide Segments ◽  
Derivatives Of

The α-ketoacid–hydroxylamine (KAHA) ligation allows the coupling of unprotected peptide segments. The most widely used variant employs a 5-membered cyclic hydroxylamine that forms a homoserine ester as the primary ligation product. While very effective, monomers that give canonical amino acid residues are in high demand. In order to preserve the stability and reactivity of cyclic hydroxylamines, but form a canonical amino acid residue upon ligation, we sought to prepare cyclic derivatives of serine hydroxylamine. An evaluation of several cyclization strategies led to cyclobutanone ketals as the leading structures. The preparation, stability, and amide-forming ligation of these serine-derived ketals are described.

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