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.

STUDY OF THE TRANSFORMATION OF NITROSYL IRON COMPLEX WITH N-ETHYLTHIOUREA LIGANDS IN MODEL BIOLOGICAL SYSTEMS

2021 ◽  
Author(s):  
Olesya Viktorovna Pokidova ◽  
◽  
Nina Sergeevna Emel’yanova ◽  
Alexander Vasilievich Kulikov ◽  
Alexander Ivanovich Kotelnikov ◽  
...  
Keyword(s):  
Amino Acid ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Reduced Glutathione ◽  
Decay Product ◽  
Iron Complex ◽  
Amino Acid Residues ◽  
Cationic Complex ◽  
Nitrosyl Iron Complex

The process of transformation of a mononuclear cationic complex with N-ethylthiourea ligands in Tris-HCl buffer, as well as in a reaction mixture with reduced glutathione and bovine serum albumin, has been studied. It was found that in the presence of glutathione, the complex dimer-izes, while its initial ligands are replaced by glutathione. In the presence of albumin, the decay product of the complex is coordinated with amino acid residues (Cys34 and His39) to form a protein-bound complex.

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 Formation and Stabilization of Gold Nanoparticles in Bovine Serum Albumin Solution

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3395 ◽  
Author(s):  
Iulia Matei ◽  
Cristina Maria Buta ◽  
Ioana Maria Turcu ◽  
Daniela Culita ◽  
Cornel Munteanu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Particle Growth ◽  
Protective Role ◽  
Amino Acid Residues ◽  
Buffer Solution ◽  
Paramagnetic Resonance ◽  
Tem Microscopy

The formation and growth of gold nanoparticles (AuNPs) were investigated in pH 7 buffer solution of bovine serum albumin (BSA) at room temperature. The processes were monitored by UV-Vis, circular dichroism, Raman and electron paramagnetic resonance (EPR) spectroscopies. TEM microscopy and dynamic light scattering (DLS) measurements were used to evidence changes in particle size during nanoparticle formation and growth. The formation of AuNPs at pH 7 in the absence of BSA was not observed, which proves that the albumin is involved in the first step of Au(III) reduction. Changes in the EPR spectral features of two spin probes, CAT16 and DIS3, with affinity for BSA and AuNPs, respectively, allowed us to monitor the particle growth and to demonstrate the protective role of BSA for AuNPs. The size of AuNPs formed in BSA solution increases slowly with time, resulting in nanoparticles of different morphologies, as revealed by TEM. Raman spectra of BSA indicate the interaction of albumin with AuNPs through sulfur-containing amino acid residues. This study shows that albumins act as both reducing agents and protective corona of AuNPs.

The Partial Purification of Two β-N-Acetyl-D-hexosaminidases from Porcine Kidney

1972 ◽  
Vol 50 (5) ◽  
pp. 563-573 ◽  
Author(s):  
Stephen J. Wetmore ◽  
Jacob A. Verpoorte
Keyword(s):  
Amino Acid ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Partial Purification ◽  
Heat Inactivation ◽  
Gel Chromatography ◽  
Porcine Kidney ◽  
Pig Kidney ◽  
Two Peaks

Two distinct fractions showing both β-N-acetyl-D-glucosaminidase (EC 3.2.1.30) and β-N-acetyl-D-galactosaminidase activity were isolated and purified from pig kidney. These preparations, which were designated A and B, were not stable during gel chromatography or prolonged dialysis. Final purifications of 600-fold for enzyme A and 440-fold for enzyme B were obtained.Gel electrophoresis and ultracentrifugation studies indicated heterogeneity in both preparations. The amino acid compositions of both preparations were very similar. Ultracentrifugation studies suggested the formation of subunits in the presence of 5 M guanidine–HCl and 1 mM dithiothreitol.A study of the enzymatic properties also showed great similarities between the two enzyme forms. Both enzymes had identical Michaelis–Menten constants of 1.88 mM for p-nitrophenyl-β-N-acetyl-D-glucosaminide and 0.38 mM for p-nitrophenyl-β-N-acetyl-D-galactosaminide. Although bovine serum albumin enhanced the activity of the enzymes it did not change the Km values. The pH-rate profiles of both enzymes with the substrate p-nitrophenyl-β-N-acetyl-D-glucosaminide showed two peaks. When p-nitrophenyl-β-N-acetyl-D-galactosaminide was used as substrate, only one peak was observed in the pH–rate profiles. However, in this case a distinct shoulder could be detected in these peaks. Heating at 50° destroyed the activities of both forms of the enzyme rapidly, but addition of bovine serum albumin protected against heat inactivation.

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