[Design of deoxyribozymes for inhibition of influenza A virus].

Influenza A viruses take a significant place in human and animal pathology causing epidemics and epizootics. Therefore, the development of new antiflu drugs has become more and more urgent. Deoxyribozymes can be considered as promising antiviral agents due to their ability to efficiently and highly specifically cleave RNA molecules.

High-performance method for specific effect on nucleic acids in cells using TiO2~DNA nanocomposites.

Nanoparticles are used to solve the current drug delivery problem. We present a high-performance method for efficient and selective action on nucleic acid target in cells using unique TiO(2)·PL-DNA nanocomposites (polylysine-containing DNA fragments noncovalently immobilized onto TiO(2) nanoparticles capable of transferring DNA). These nanocomposites were used for inhibition of human influenza A (H3N2) virus replication in infected MDCK cells.

DNA methyltransferases: mechanistic models derived from kinetic analysis.

The sequence-specific transfer of methyl groups from donor S-adenosyl-L-methionine (AdoMet) to certain positions of DNA-adenine or -cytosine residues by DNA methyltransferases (MTases) is a major form of epigenetic modification. It is virtually ubiquitous, except for some notable exceptions. Site-specific methylation can be regarded as a means to increase DNA information capacity and is involved in a large spectrum of biological processes.

[Design of oligonucleotide inhibitors of the human DNA-methyltransferase 1].

Mammalian DNA methyltransferase 1 (Dnmt1) is responsible for copying DNA methylation patterns during cell division. A number of studies demonstrate that Dnmt1 plays an important role in carcinogenesis, that causes, in particular, significant interest in searching for specific inhibitors of this enzyme. In the present study, with the purpose of design of oligonucleotide inhibitors of human Dnmt1, a number of single-, double-stranded and hairpin DNA-structures, containing canonical or modified enzyme recognition site 5'-CG were constructed on the basis of uniform 22 b sequence.

Dimeric/oligomeric DNA methyltransferases: an unfinished story.

DNA methyltransferases (MTases) are enzymes that carry out post-replicative sequence-specific modifications. The initial experimental data on the structure and kinetic characteristics of the EcoRI MTase led to the paradigm that type II systems comprise dimeric endonucleases and monomeric MTases. In retrospect, this was logical because, while the biological substrate of the restriction endonuclease is two-fold symmetrical, the in vivo substrate for the MTase is generally hemi-methylated and, hence, inherently asymmetric.