Features of ultrastructural changes of tumor cells in tissue culture under the effect of energy metabolism inhibitors

It is shown that 2,4-dinitrophenol and dicyclohexylcarbodiimide, energy metabolism inhibitors, induce regular specific changes of the HeLa culture cells ultrastructure. Peculiarities of metabolism of the tumor cells as against the normal culture cells cause weaker and slower response.     

Identification of various hydrophobic zones in microsomal membranes containing cytochrome P-450 binding sites for type I and II substrates

Two different phospholipid hydrophobic zones in the membrane associated with cytochrome P-450 were identified. One of them exhibits selective sensitivity towards the protonated influence of carbonylcyanide-m-chlorophenyl hydrazone and possesses binding sites for type I substrates. The second one includes the heme group of cytochrome P-450 and herein the binding sites for type II substrates. Sodium deoxycholate (0.75-2.0 mM) disrupts both zones. Subsequent incorporation of fluorine atoms into a type II substrate (aniline) results in the increase in the hydrophobicity of aniline halogenated derivatives and in changes in the substrate-binding sites for tetra- and pentafluoroanilines from the heme-iron sphere to the apoenzyme of cytochrome P-450.     

Morphological and Molecular Genetic Verification of Interspecific Hybrid Salix × zhataica (Salicaceae) from Central Yakutia

Russian Journal of Genetics - The results of morphological and molecular genetic analysis confirming the hybrid nature of Salix × zhataica Efimova, Shurduk et Ahti are presented. In...     

Conformation of the denatured DNA molecule in solutions of different ionic strengths]

The conformation of the denatured DNA molecule of different molecular weights in the solutions of various ionic composition was studied by the methods of viscometry, light scattering and flow birefringence. Formaldehyde purified from metallic ions with the help of ionites was used for fixation of the denatured state of the DNA molecule. It has been shown that theories developed for flexible macromolecules are in a sufficient accordance with hydrodynamical and optical data. The unperturbed dimensions, equilibrium rigidity of the macromolecule in solutions of different ionic strengths, mu, were determined. In the range of mu greater than or equal to 0.005 the length of Kuhn's segment (A) is equal to approximately 40 A and its value increases with an increase of mu. At mu 0.001 A approximately 60 A and mu 0.0005 A approximately 85 divided by 100 A. A relation between intrinsic viscosity and molecular weight of the denatured DNA molecule was established. Data on the flow birefringence in the solutions of the denatured DNA have shown that the sigh of optical anisotrophy of the macromolecule depends on the ionic strength. The observed dependency may be explained only by assuming that ionic strength influences the equilibrium orientation of nitrogen base planes with respect to the main chain of the macromolecule.