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.

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.

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.

Influence of anticarcinogenic metalloporphyrin Cu(II)TOEPyP(4) on DNA thermostability in vitro.

The influence of a new anticarcinogenic compound Cu(II)TOEPyP(4) (Cu(II)-Meso-tetra(4-N-oxyethylpyridyl) porphyrin) (the analogue of TMPy4[tetra(N-mrthyl-4-pyridyl)-porphyrin chloride] - an inhibitor of telomerase activity - on the thermostability of calf thymus DNA in vitro has been studied. It has been shown that Cu(II)TOEPyP(4) is a stronger stabilizing DNA agent, which is expressed with an increase of its thermostability by 20 degrees C. It was determined that complex formation does not disturb the DNA double-helix, and the melting enthalpy (DeltaHm) remains unchanged and it is equal to 11.

Microcalorimetric investigation of DNA, poly(dA)poly(dT) and poly[d(A-C)]poly[d(G-T)] melting in the presence of water soluble (meso tetra (4 N oxyethylpyridyl) porphyrin) and its Zn complex.

Thermodynamic parameters of melting process (DeltaHm, Tm, DeltaTm) of calf thymus DNA, poly(dA)poly(dT) and poly(d(A-C)).poly(d(G-T)) were determined in the presence of various concentrations of TOEPyP(4) and its Zn complex. The investigated porphyrins caused serious stabilization of calf thymus DNA and poly poly(dA)poly(dT), but not poly(d(A-C))poly(d(G-T)).