Bìofìzičnij Vìsnik

5-10

Authors: V.M. Trusova

Using 8 web-algorithms, including Pasta2, AmylPred2, Tango, MetAmyl, Waltz, Aggrescan, BetaScan та FoldAmyloid, theoretical analysis of amino acid sequences of lysozyme, cytochrome c and N-terminal fragment of apolipoprotein A-I has been carried out, and amyloidogenic fragments of the proteins have been identified. The fragment was identified as amyloidogenic if it was determined by at least four algorithms. Comparative analysis of aggregation-prone regions of native and mutant proteins showed that that all mutants are characterized by same amyloidogenic segments as native proteins with the amyloidogenic potential being more pronounced for mutated proteins. It was shown that aggregation-prone regions of all proteins analyzed here, were rich in hydrophobic aliphatic (Ile, Val, Leu, Ala) and aromatic (Trp, Phe, Tyr) amino acid residues. Hydrophobic interactions were supposed to play key role in protein aggregation process.

19-26

Authors: K. А. Kuznetsov, О. Т. Nikolov, Y. G. Shckorbatov

Modulation of the biological effects produced by ionizing radiation (IR) using microwave and magnetic fields has important theoretical and practical applications. Response of human buccal epithelium cells to different physical agents (single and combined exposure to 0.5–5 Gy γ-radiation (60Co); microwaves with the frequency of 36.64 GHz and power densities of 0.1 and 1 W/m2, and static magnetic field with the intensity of 25 mT) has been investigated. The stress response of the cells was evaluated by counting heterochromatin granules quantity (HGQ) in the cell nuclei stained with orcein. Membrane permeability was assessed by the percentage of cells stained with indigocarmine (cells with damaged membrane). The increase of heterochromatin granules quantity (HGQ), i.e. chromatin condensation was detected at the doses of 2 Gy and higher. Changes in the cell membrane permeability to indigocarmine expressed the threshold effect. Membrane permeability reached the threshold at the doses of 2–3 Gy for the cells of different donors and did not change with the increase of the dose of γ-radiation. Cells obtained from different donors revealed some individual peculiarities in their reaction to γ-radiation. The static magnetic field and microwaves applied before or after γ-radiation decreased its impact, as revealed by means of HGQ assessment.

37-42

Authors: K. O. Vus, V. M. Trusova, G. P. Gorbenko, P. Kinnunen

Amyloid fibrils are the protein aggregates, whose formation is involved in the pathogenesis of Alzheimer’s disease, systemic amyloidosis, etc. Since there is no effective ways to treat these diseases, developing the new anti-amyloid drugs is of great importance. In this study a series of phospholipids have been tested for their ability to inhibit lysozyme and insulin amyloid fibril formation at acidic or neutral pH and elevated temperature. The lag time, elongation rate and fibrillization extent were estimated using Thioflavin T fluorescence assay. It is found that the oxidized and charged phospholipids, included into the liposomes, were the most effective inhibitors of the protein fibrillization. By comparing the magnitude and direction of the lipid effect in different lipid-protein systems it was concluded that the reduction of the amyloid fibril formation is governed by hydrophobic and specific liposome-protein interactions. It is hypothesized that the presence of the surface formed by the lipid polar heads is critical for reducing the protein fibrillization extent.

51-62

Authors: L.I. Kobylinska, T.S. Malyy, S.V. Apunevych, I.G. Mankovska, A.S. Voloshynovsky, O.M. Klyuchivska, R.S. Stoika, R.B. Lesyk, B.S. Zimenkovsky

This study was aimed at measurement of the transmission, luminescence spectra, and luminescence excitation spectra of three novel anticancer 4-thiazolidinone derivatives (ID 3288, ID 3882, ID 3833) in order to characterize the photoinduced cytotoxicity of these compounds against murineleukemia L1210 cell line. The luminescence and luminescence excitation spectra of the ID 3288, ID 3882 and ID 3833 powders differed significantly from those measured in aqueous solution. Furthermore, the luminescence of the ID 3288 powder had lower intensity as compared to that of the ID 3882 and ID 3833 powders. The luminescence of the ID 3882 aqueous solution showed the lowest intensity, while the ID 3833 demonstrated the highest intensity. The potential of application of the obtained results in the photodynamic anticancer chemotherapy has been discussed.

5-9

Authors: M.A. Bondarenko, V.G. Knigavko, N.O. Gordiyenko, O.V. Zaytseva, T.R. Kocharova

Carcinogenesis is subject of the research. The research aims at creating the mathematical model of carcinogenesis allowing assessing the distribution in human population of the genes which when damaged lead to oncology diseases. The main task is to build a probability mathematical model describing the quasistationary equilibrium of two contrary processes, and namely: 1) the process of reduction in population of the number of the aforesaid genes due to their mutative damage; 2) increase in population of the number of these genes due to the fact that persons with a few genes of the kind in their genotype acquire oncological diseases with higher probability at early stages of their lives and do not manage to reproduce themselves before they die, and so the growth of the total population size is more due to the reproduction of individuals with a high number of the a-genes. Assessment of the distribution of these genes in the population was carried out by determining the probability that a randomly selected individual from the population has one of the possible values (according to the literature, from 0 to 8) of the aforementioned genes.

21-27

Authors: D. M. Glibitskiy, G. M. Glibitskiy, M. A. Semenov, A. V. Shestopalova

Analysis of the patterns on the dried films of biological fluids is a promising avenue of medical diagnostics and biosensors development. The aim of this work was to study the effect of iron and copper ions on the quantitative characteristics of textures and zigzag patterns (Z-structures) observed on the films of saline solutions of bovine serum albumin (BSA). In the experiment, 0.5 mg/ml BSA, 20 mM/l NaCl, 0.05 mM/l CuCl2 and 0.2÷0.05 mM/l FeCl3 were used. For textures, the area and fractal dimension were estimated, and for zigzag patterns, area and the specific length of the Z-structures were estimated. The effect of iron and copper ions on the geometrical parameters of Z-structures was analyzed. Spatial distributions of the fractal dimension of texture and the specific length of Z-structures were analyzed. It was shown that using the product of all four parameters increases the sensitivity of the method compared to using only one of the parameters. The method can be used in pharmacology and medical biochemistry for screening drugs and chemical compounds by their degree of influence on biopolymers.

34-45

Authors: M. A. Popirny, O. T. Nikolov, E. V. Skrylnik

The purpose of this work lies in studying the composition, physical and chemical properties of the second fraction of the humic acid (HA2) extracted from the typical black soil, depending on the intensity of the soil tillage. Physical and chemical properties of HA2 have been studied by using ultraviolet (UV) spectroscopy, infrared (IR) spectroscopy and electron spin resonance spectroscopy (ESR). It has been demonstrated that increase of the tillage intensity of the typical black soil leads to decrease in the total carbon content and the HA2 content due to displacement of balance between the conjugated processes of humus synthesis and decay towards destruction. UV spectroscopy indicates intense absorption of humic acids in the near UV region, that corresponds to the donor-acceptor mechanisms π-π* electrons of double bonds. Maximum absorption has been observed for the HA2 isolated from the black soil tilled by plowing. Moreover, the highest content of oxygen-containing functional groups and low quantity of aliphatic structures has been observed in the same sample. It has been shown that the nature of paramagnetic centers of the HA2 represented by chelate paramagnetic Fe3+-complex formed by rearrangement π-electron system of double bonds, depending on the tillage intensity of the typical black soil. It has been found that plowing of the typical black soil enhances the number of paramagnetic centers in HA2.