Conformations of DNA in the presence of nanomole concentrations of Co+2 ions and mezo-tetra(4-N-oxyethylpiridil) porphyrin.

Conformation changes of calf thymus DNA induced by nanomole concentrations of Co(+2) and TOEPyP4 and influence of this ion on porphyrin binding mode with DNA duplex were studied at two NaCl concentrations (10 and 100 mM) using circular dichroism spectroscopy and absorption data. It was shown that addition of 85 nM Co(+2) into TOEPyP4/DNAb.p.

Influence of tetrapeptide on chromatin thermostability.

It is known that short peptides are capable to interact with DNA, as a result of changes in particular gene expression. In the given work, influence of Ala-Asp-Glu-Leu peptide on thermostability of white rat liver chromatin, in which H1 histone and non-histone proteins are depleted, have been studied. It was shown that in 10 nm chromatin filaments, in which nucleosomas do not interact, the tetrapeptide unfolds the nucleosomal nucleus (core) and this causes release of about 15% of core DNA that melts in the melting temperature range of internucleosomal linker DNA.

Effect of the peptide bronchogen (Ala-Asp-Glu-Leu) on DNA thermostability.

Thermodynamic parameters of DNA melting in the presence of a peptide bronchogen in various concentrations were estimated on a differential scanning microcalorimeter. Bronchogen was shown to serve as a DNA-stabilizing agent. Bronchogen increased the melting temperature of DNA from calf thymus and mouse liver by 3.

Remodeling of heterochromatin induced by heavy metals in extreme old age.

The levels of chromosome instability and heat absorption of chromatin have been studied in cultured lymphocytes derived from blood of 80-93- and 18-30-year-old individuals, under the effect of heavy metal Cu(II) and Cd(II) salts. The analysis of the results obtained indicates that 50 μM Cu(II) induced a significantly higher level of cells with chromosome aberrations in old donors (13.8 ± 1.

Gerontology research in Georgia.

Gerontology research carried out in different scientific centers of Georgia follows the basic directions of most work in this field: epidemiology, investigation of the mechanisms of aging, and finding ways to prevent senile pathologies and to prolong life. The genealogy and epidemiology of long-living peaple have been studied in areas with high occurrence of these people by considering the sex ratio and social status of the long-living, the influence of environmental factors, and the development of senile pathologies. According to the centrosome (centriole) model of aging, the centrosomes and the cytoskeleton, important structures in cellular differentiation and morphogenesis, may be involved in the initiation of the replication senescence mechanism.