Modification of hydrophobic sorbents by cobalt chloride in order to concentrate low molecular polar organic substances from the air for subsequent gas chromatographic determination.

The article presents a new method of modification of hydrophobic sorbents. To improve sorption pre-concentration of polar organic compounds in the air analysis, these sorbents are coated with cobalt chloride. This modification increases retention volume of lower alcohols by 5-10 fold as compared to that of unmodified sorbents and solves the problem of gas-chromatographic determination at 1-2 ppb (micrograms/m(3)) by using the most common flame ionization detector.

[The birth and death of genes].

Duplications of DNA regions with subsequent divergence of the duplicated copies by mutations is traditionally considered to be the major mechanism of the new genes appearance. After duplication, only a small fraction of the paralogs remains unchanged, while most copies are converted into pseudogenes or acquire new functions as a consequence of either subfunctionalization or neofunctionalization events. In some cases, certain regions of duplicated copies can combine with each other, giving rise to functionally new genes.

[Modification of [PSI+] prion properties by the combination of amino acid changes within Sup35 protein N-domain].

[PSI+] prion is an amyloid isoform of a release factor Sup35p (eRF3). The structure of these protein aggregates remains unclear despite a long term history of prion amyloids investigations. The N-terminal domain of Sup35p (which is responsible for a propagation of prion) shapes superpleated beta-structure, according to modern concepts.

[The identification of Saccharomyces cerevisiae genes leading to synthetic lethality of prion [PSI+] with Sup45 mutations].

Previously, we proposed a test system allowing to perform search for genes that influence the properties of the Sup35 and Sup45 protein. This test is based on the phenomenon of lethality of diploids that combine mutations in SUP45 gene with [PSI+] prion. Lethality of this combination depends on the type of sup45 mutation, and the properties of the prion.

[The influence of UPF genes on the severity of SUP45 mutations].

Eukaryotic cells possess special mechanism of the degradation of mRNAs containing premature termination codons (PTCs)--nonsense-mediated mRNA decay (NMD) pathway. In yeast Saccharomyces cerevisiae, the activity of this pathway depends on the recognition of the PTC by the translational machinery and interaction of translation termination factors eRF1 and eRF3 with Upf1, Upf2 and Upf3 proteins. Previously we have shown that decreasing of eRF1 amount causes an impairment of NMD.