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V V Vlassov

Publications and source records attributed to V V Vlassov.

At least 91 records · Page 5Linked to original sources
PubMed1985

Nucleotide and oligonucleotide derivatives as enzyme and nucleic acid targeted irreversible inhibitors. Chemical aspects.

Reactive derivatives of nucleic acid components are the promising affinity reagents for specific modification of nucleic acids and nucleic acid-related proteins. Reactive ATP derivatives synthesized using the simple method described in the present chapter are potent specific inhibitors of various enzymes interacting with ATP. Reactive oligonucleotide derivatives bind to complementary nucleotide sequences in nucleic acids and modify them in the neighborhood of the binding area. Modification with these derivatives (complementary addressed modification) may become an efficient approach for specific arrest of certain cellular biopolymer biosynthesis and for site-directed mutagenesis. In this chapter, synthesis of alkylating oligonucleotide derivatives is described in detail and the results of their application for modification of nucleic acids in vitro are summarized. The results allow one to think about future biochemical and biomedical applications of complementary addressed modification.

Alkylation↗
PubMed1985

Nucleotide and oligonucleotide derivatives as enzyme and nucleic acid targeted irreversible inhibitors. Biochemical aspects.

Sequence specific modification of nucleic acids with reactive oligonucleotide derivatives, complementary addressed modification, can provide an efficient approach for specific inactivation of certain cellular nucleic acids. In experiments with ascites tumor Krebs II cells and alkylating oligothymidylate derivatives it was found that alkylating oligonucleotide derivatives enter the living cell and modify complementary sequences in cellular nucleic acids with high efficiency. Complementary addressed modification of poly(A) sequences in cellular RNA with oligothymidylate derivatives was investigated in detail. The results of experiments on alkylation of cellular nucleic acids are consistent with complementary addressed modification of poly(A) sequences in cellular DNA. These results are supported by experiments on modification of chromatin DNA in which it was found that chromatin DNA interacts with oliogothymidylate derivatives more readily than the isolated double stranded DNA. It was found that alkylating oligonucleotide derivatives complementary to a sequence in immunoglobulin mRNA of MOPC 21 cells arrest the cellular immunoglobulin synthesis. Alkylating oligonucleotide derivatives complementary to RNAs of fowl plague virus inhibit virus multiplication in cell culture.

Alkylation↗
PubMed1983

Interaction of tRNAPhe and tRNAVal with aminoacyl-tRNA synthetases. A chemical modification study.

The alkylation by ethylnitrosourea of phosphodiester bonds in tRNAPhe from yeast and in tRNAVal from yeast and from rabbit liver and that by 4-(N-2-chloroethyl-N-methylamino)-benzylamine of N-7 atoms of guanosine residues in yeast tRNAVal have been used to study the interaction of these tRNAs with aminoacyl-tRNA synthetases. The modifications occurring at low yield were carried out on 3' and/or 5' end-labelled tRNAs either free or in the presence of cognate or non-cognate synthetases. After splitting of the tRNAs at the alkylated positions, the position of the modification sites in the tRNA sequences were detected by acrylamide gel electrophoresis. It was found that the synthetases protect against alkylation certain phosphate or guanosine residues in their cognate tRNAs. Non-cognate synthetases failed to protect efficiently specific positions in tRNA against modification. In yeast tRNAPhe the cognate phenylalanyl-tRNA synthetase protects certain phosphates located in all four stems and in the anticodon and extra-loop of the tRNA. Particularly strong protections occur on phosphate 34 in the anticodon loop and on phosphates 23, 27, 28, 41 and 46 in the D and anticodon stems. In yeast tRNAVal complexed with yeast valyl-tRNA synthetase the protected phosphates are essentially located in the corner between the amino-acid-accepting and D stems, in the D loop, anticodon stem and in the variable region of the tRNA. Three guanosine residues, located in the D stem, and another one in the 3' part of the anticodon stem were also found protected by the synthetase. In mammalian tRNAVal, complexed with the cognate but heterologous yeast valyl-tRNA synthetase, the protected phosphates lie in the anticodon stem, in the extra-loop and in the T psi arm. The location of the protected residues in the structure of three tRNAs suggests some common features in the binding of tRNAs to aminoacyl-tRNA synthetases. These results will be discussed in the light of informations on interaction sites obtained by nuclease digestion and ultraviolet cross-linking methods.

Alkylation↗
PubMed1981

Tertiary structure of tRNAs in solution monitored by phosphodiester modification with ethylnitrosourea.

The alkylation by ethylnitrosourea of phosphodiester bonds in yeast tRNAPhe, tRNAVal and in Escherichia coli tRNAGlu, tRNAfMet, tRNAmMet and tRNAPhe was investigated under various conditions. In unfolded tRNAs the reactivities of phosphates in various positions toward the reagent were similar. In the folded tRNAs remarkable differences in reactivities of phosphates located in various positions of the molecules were observed. In yeast and E. coli tRNAPhe, reactivities of phosphates in positions 9, 10, 11, 19, 49, 58, 59 and 60 were found to be strongly decreased. Some decrease in reactivity was observed for phosphates 23 and 24. Spermine and ethidium bromide did not influence the pattern of phosphate alkylation in the T psi C arm of yeast tRNAPhe. Our solution results fit with the crystal structure of tRNAPhe with respect to the potential availability of the phosphates in this tRNA to solvent as shown by others. Judging from the pattern of phosphate reactivities, the structure of E. coli tRNAPhe is very similar to that of yeast tRNAPhe. Upon thermal denaturation of the yeast tRNAPhe, the reactivity of the low-reactive phosphates increased, demonstrating a cooperative melting curve. A comparison of the patterns of phosphate alkylation in several tRNAs, essentially in their T psi C arms, revealed a striking similarity, suggesting that the folding of these tRNAs is essentially similar.

Alkylation↗
PubMedDate not supplied

Interaction of LNA oligonucleotides with mdr1 promoter.

LNA oligonucleotides [1] can be used for targeting to double stranded DNA by the "strand invasion" mechanism. We used affinity modification by reactive oligonucleotide conjugates for investigation of oligonucleotides interaction with structured DNA. The tested LNAs and oligonucleotides of the same sequence were assayed as anti-mdr1 drugs in different cell cultures. One of the oligos, LNA79 strongly inhibited mdr1 induction in Hela cells and totally prevented activation of mdr1 in K-562.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Cu(2+)-dependent DNA-cleaving activity of arenes.

In the presence of Cu(II) ions, plasmid DNA is cleaved under physiological condition by different arenes at low concentrations. The cleavage was dependent on the presence of O2. The DNA cleavage efficiency of the designed system arene-Cu is comparable to that of the well-known DNA cleaving reagents such as phenanthroline-Cu and ascorbic acid-Cu. However in contrast to the mentioned reagents, the system arene-Cu does not require external reducing agents or H2O2.

Copper↗
PubMedDate not supplied

Glyceraldehyde-3-phosphate dehydrogenase is responsible for intranuclear localization of some oligonucleotides.

Nuclear accumulation of ODNs has been associated with their binding to a series of nuclear proteins. These interactions could be responsible for the sequence-independent effects of ODNs as well as for their sequence-specific interactions and their intracellular distribution. Investigation of interaction of ODNs with these proteins may shed light on the mechanisms of cellular uptake and nuclear accumulation of oligonucleotides.

Binding, Competitive↗
PubMedDate not supplied

New reagent for protein-DNA contacts footprinting.

We have found, that the reaction of o-bromobenzoic acid with Cu2+ ions can be used as a source of activated oxygen species capable of cleaving DNA. Possibility to apply this reaction for footprinting the nucleosome core in the reconstituted chromatin was demonstrated.

Binding Sites↗