[Hyperchromism of nucleic acids in the infrared region].
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Animals↗
Biomedical subjects
V Ia Maleev
Publications and source records attributed to V Ia Maleev.
[Why must the collagen denaturation temperature be close to the temperature at which the species developed?].
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Animals↗
[Spectroscopic evidence of the interaction of the dye pyronine G with polynucleotides].
The interaction of pyronine G with mono- (AMP) and polynucleotides, i. e. poly(A) and poly(U), was studied at different pH values and temperatures, both in the visible and near UV ranges. It was found that pyronine G interacts only with purine type polynucleotides at neutral and alkaline pH. This was confirmed by the appearance of a new dye absorption band in the visible range and the existence of a hypochromic effect in the UV. The spectroscopical evidence for the formation of pyronine G--AMP or poly(U) complex has not been found at any conditions. With these results in view, possible binding mechanism of pyronine G to polynucleotides are discussed.
Adenosine Monophosphate↗
[Thermogravimetric study of the stability of DNA hydrate].
Thermograviometric study of DNA hydrate in the temperature range 0--120 degrees C was carried out. The three-stage hydration was observed: the first stage within 20--32 degrees C, the second--70--95 degrees C and the third one--105--116 degrees C. An assumption is advanced concerning the nature of structural rearrangements related to the loss of water in the system DNA--water. High sensitivity of thermograviometry to initial water content in DNA hydrate was shown.
Chemical Phenomena↗
[Are nitrogen bases of DNA hydrated at low humidity?].
The infrared spectra (1450-1800 cm-1) of DNA films derived at different relative humidity are presented. An analysis of the observed frequency and intensity changes of infrared bonds assigning to the intra- and interring vibrations indicates that the nitrogen bases of DNA become hydrated at low (0-64%) relative humidities.
Chemical Phenomena↗
[Spectrophotometric complexes of nucleic acids with pyronine G dyes as a test for radiation damage of DNA].
The spectrophotometric titration curves of the complexes of polynucleotide matrix with pyronine G are highly specific depending on the type and conformation of polyelectrolyte (native and denatured DNA, polyribonucleotides, tRNA). It is found that DNA from the liver of experimental animals of different age, permanent inhabitants of the Chernobyl zone, forms complexes with RNA. A method for testing the defects in a DNA secondary structure have been developed based on comparative analysis of the spectra for the complexes of different nucleic acids with dyes and relative curves of spectrophotometric titration.
Animals↗
[Thermal restructuring and hydration of serum albumin].
Calorimetry and dielectrometry in the millimeter wave range have been applied to demonstrate a possibility for determination of heat capacity of bound water in biopolymer matrices in solution is shown. Variation of the hydration level of human serum albumin caused by the variation of temperature and protein concentration is described. Application of two methods based on comparison of calorimetric and dielectric data on protein solutions at different temperatures and concentrations have produced similar values of the heat capacity of bound water in the protein hydration shell (approximately 3 J/g.K).
Biopolymers↗
[Hydration and stability of the double helical complex poly(dA)-poly(dT)].
IR-spectrometry and thermopiezogravimetry are used to study the structure formation and the water environment of the double-helix Na-poly(dA)-poly(dT) complex in films in the 0-100% interval of the relative humidity (RH). It has been found that three different structures of the complex are formed in the 0-32, 32-76 and 88-100% intervals of RH. The calculations of resonance frequencies of out-of-ring (C-0) and in-ring (C-N) vibrations in adenine and thymine using perturbation theory show that the second and the third forms are the X-ray beta-B'- and alpha-B'-forms. Distribution of the binding energy of water molecules has been found from IRS data about water sorption and isotherms of hydration at different temperatures. The enthalpy of helix-coil transition has been found from microcalorimetry data. These results allow us to estimate the energy contribution of water molecules (about 75%) and other interactions (about 25%) in the total stabilization energy of the complex structure.
Polydeoxyribonucleotides↗
[Hydration and structural state of liver DNA of rats exposed to radiation in the Chernobyl AES zone].
By methods of IR-spectroscopy, electrophoresis and piezomicrobalance the comparative study on hydration and structural state of liver DNA from rats both intact and exposed within the Chernobyl accident zone was conducted. Modification of primary and secondary DNA structure in irradiated animals demonstrate serious disturbance of hepatocyte genetic apparatus. This is responsible for previously found considerable morphologic and ultra-structural changes in rat liver tissue after prolonged exposure to low-level ionizing radiation in the Chernobyl accident zone.
Accidents↗
[Hydration and stability of the B-form of LiDNA].
Hydration and structure of Li DNA in films and solutions have been investigated by methods of IR spectroscopy, piezogravimentry, UHF dielectrometry, and microcalorimetry. The hydration energy and the water sorption range in which the DNA undergoes the transition from the unordered state to the B-form have been determined, making it possible to evaluate the contribution of water molecules of the DNA hydration shell to the total stabilization energy of the DNA helical structure.
Calorimetry↗
[Physical properties of the DNA-water system].
The review of original and literary data obtained by the different physical methods on the structure, mechanical, electrostatic and energetic properties of DNA-ions-water system was done. On the basis of the examined results the main problem of DNA structure formation its dynamic and stability were discussed.
Base Sequence↗
[Effect of water on the structural modification and stabilization of DNA from Clostridium perfringens].
By the methods of infrared spectroscopy, piezogravimetry and microcalorimetry the process of forming of the structure and hydration environment of DNA from Clostridium perfringens in the wet films has been investigated. It were found three intervals of relative humidity (r.h.) in which three structural states of DNA: an unordered state (0-44% r.h.), the A-form (46-75% r.h.) and the B-form (80-86% r.h.) are realized. We measured the heat of water evaporation from the DNA-water samples with the differential scanning microcalorimeter. From these calorimetric data the distribution of the water molecules on the bond energy with DNA was determined. The contribution of the water molecules of hydration shell (73%) and hydrogen bonds in the Watson-Crick pairs (27%) to the total energy of stabilization of the helical B-form DNA from Cl. perfringens has been evaluated.
Clostridium perfringens↗