Interaction of new fluorescent ict-dyes with lipid membranes

The present study was undertaken to evaluate the sensitivity of newly synthesized ICT dyes to the changes in physicochemical properties of lipid bilayer. Partitioning of ICT4 into lipid phase of the model membranes composed of zwitterionic lipid phosphatidylcholine (PC) and its mixtures with anionic lipid cardiolipin and cholesterol was followed by the decrease of fluorescence quantum yield and short- wavelength shift of emission maximum. On the contrary, ICT2 exhibited tenfold increase of the quantum yield upon interaction with liposomes, without any shift of the emission maximum. Analysis of the partition coefficients showed that inclusion of cardiolipin and choleterol into phosphatidylcholine bilayer gives rise to increase of the ICT2 incorporation into lipid phase compared to the neat phosphatidylcholine membrane

Fluorimetric study of interaction between europium coordination complexes and DNA

Lanthanide coordination complexes have found numerous applications in a number of areas, including laser techniques, fluorescent analysis, biomedical assays. Likewise, they exhibit antitumor properties. Eu(III) tris-β-diketonato complexes (EC) are newly synthesized compounds with high anticancer activity. Despite extensive studies, the detailed mechanism of their biological effects is far from being resolved. Examining the interactions between EC and biological molecules in model systems is essential for deeper understanding of the mechanisms behind their biological activity. In the present work we employed fluorescent probe acridine orange (AO) to investigate EC-DNA interaction. AO-DNA binding was followed by the marked fluorescence increase detected at 530 nm. EC addition suppressed this fluorescent changes. EC were found to differ in their ability to modify AO-DNA interactions. EC4 and EC6 have demonstrated the most pronounced effect on AO-DNA binding. AO-DNA complexation occurs predominantly via intercalation mode. EC are large planar structures, whose DNA intercalating ability was reported to increase with the planarity of ligands. It seems likely that AO and EC can compete for the binding sites on DNA molecule

О неустойчивости решений динамических уравнений на временной шкале

В роботi наведено результати аналiзу нестiйкостi динамiчних рiвнянь на часовiй шкалi. Застосовнiсть отриманого результату iлюструється на прикладi системи другого порядку.We present new results on the instability for dynamic equations on time scales. To demonstrate the applicability, we use some examples of dynamic equations of the second order

Interaction of new fluorescent ict-dyes with lipid membranes

The present study was undertaken to evaluate the sensitivity of newly synthesized ICT dyes to the changes in physicochemical properties of lipid bilayer. Partitioning of ICT4 into lipid phase of the model membranes composed of zwitterionic lipid phosphatidylcholine (PC) and its mixtures with anionic lipid cardiolipin and cholesterol was followed by the decrease of fluorescence quantum yield and short- wavelength shift of emission maximum. On the contrary, ICT2 exhibited tenfold increase of the quantum yield upon interaction with liposomes, without any shift of the emission maximum. Analysis of the partition coefficients showed that inclusion of cardiolipin and choleterol into phosphatidylcholine bilayer gives rise to increase of the ICT2 incorporation into lipid phase compared to the neat phosphatidylcholine membrane

Modulation of Mitochondriotropic Properties of Cyanine Dyes by in Organello Copper-Free Click Reaction

Cyanine dyes show a general propensity to localize to polarized mitochondria. This mitochondriotropism was used to perform a copper-free click reaction in the mitochondria of living cells. The in organello reaction of a Cy3 and Cy5 dye led to a product that was easily traceable by Förster resonance energy transfer (FRET). As determined by confocal laser scanning microscopy, the Cy3-Cy5 conjugate showed enhanced retention in mitochondria as compared to the starting compounds. This enhancement of a favorable property can be achieved by synthesis in organello but not outside mitochondria