Affinity modification of the 40S subparticle from human placenta with derivatives of pAUG and pAUGU3]

Affinity labeling of 40S subunits from human placenta with 4-(N-2-chloroethyl-N-methylamino)benzylmethyl-[32P]phosphoamide s of oligoribonucleotides pAUG and pAUGU3 was studied. Covalent attachment of these derivatives to 40S subunits within the complexes with 40S subunits, formed in the presence of Met-tRNAf.eIF-2.GTP, was detected. Both rRNA and ribosomal proteins were modified. Fragments of 18S rRNA, containing sites of the reagent attachment were identified: 1058-1164 for pAUG derivative and 976-1057--for pAUG and pAUGU3 ones. The data obtained allowed to conclude that the presence of the neighbouring codon at the A-site, regardless of the presence of the tRNA in it, affects significantly the arrangement of the trinucleotide template in the codon-anticodon interaction region. The large subunit does not cause significant alterations in the structural organization of the codon-anticodon interaction region.     

Cholesterol-modified anti-<Emphasis Type="Italic">MDR1</Emphasis> small interfering RNA: Uptake and biological activity

Small interfering RNAs (siRNA) are considered to be potential agents for specific gene silencing, but low the efficacy of siRNA delivery into cells limits their biomedical application. Accumulation of siRNA coupled with cholesterol residue at the 5′-end of the “sense” strand (chol-siRNA) was studied in HEK293, HepG2, SC1, and KB-8-5 cells. In the absence of a transfection agent, the levels of both carrier-free and chol-siRNAs were very low, whereas transfection agent substantially increased transfection rate in all cell lines; in HEK293, SC1, and KB-8-5 cells transfection efficiency of the chol-siRNA was higher than that of the corresponding unmodified siRNA. Biological activity of anti-MDR1-siRNAs targeted to the 557–577 nt region of the MDR1 gene mRNA was estimated as multiple drug resistance phenotype reverting activity of KB-8-5 cancer cells. The chol-siRNA induced cancer cells’ death in the presence of previously tolerated vinblastine doses more effectively than unmodified siRNA.     

State of the population of myriapodes <Emphasis Type="Italic">Monotarsobius curtipes</Emphasis> in the impact area of Aluminum Plant

The structure of the population and size characteristics of myriapodes Monotarsobius curtipes C. Koch, 1847 in the zone affected by the Kandalaksha Aluminum Plant (Murmansk oblast) were investigated. Comparison with the background territories shows a reliable decrease in quantitative characteristics of the population (numbers, biomass, occurrence), distortions of the sex and age structure and reproductive dynamics, a directive effect of selection towards an increased fractions of males and females with medium body size and elimination of adult individuals of both sexes with the largest and the smallest size of body.     

Perfluoroarylazide derivatives of 2'-O-modified oligoribonucleotides: efficient reagents for RNA photomodification

Site-specific photomodification of the 5'-terminal fragment of MDR1 mRNA by perfluoroarylazide derivatives of 2'-O-modified (2'-O-methyl or 2'-O-tetrahydropyranyl) oligoribo- and oligodeoxyribonucleotides was investigated. The conjugates built of 2'-O-modified oligoribonucleotides demonstrate beneficial features compared with their deoxyribo analogs: the extent of RNA modification by 2'-O-modified oligoribonucleotides and oligodeoxyribonucleotide conjugates was 40- 50% and 20%, respectively.     

Antisense oligonucleotides inhibiting ribosomal functions in mycobacteria

We studied the binding of antisense oligonucleotides with 23S rRNA of mycobacteria and E. coli and identified oligonucleotides with selective affinity to the -sarcin loop region of 23S rRNA of M. tuberculosis and to 70S ribosomes of M. smegmatis. These oligonucleotides proved to selectively inhibit protein synthesis on M. smegmatis ribosomes.Translated from Izvestiya Akademii Nauk, Seriya Biologicheskaya, No. 2, 2005, pp. 133–140.Original Russian Text Copyright © 2005 by Demchenko, Zenkova, Vlassov.