V. F. Zarytova

Oligonucleotide Conjugated to Linear and Branched High Molecular Weight Polyethylene Glycol as Substrates for RNase H

Two conjugates of an anti-HIV oligonucleotide (ODN) with different high molecular weight monomethoxy polyethylene glycols (MPEGs) have been tested for their activity as substrate towards RNase H. The MPEG does not impede the formation of the regular hybrid duplex with the target RNA sequence as pointed out by the persistence of the RNase H activity; thus, these derivatives stimulate the hydrolysis of RNA by the enzyme at the same site and with the same extent of cleavage as the native sequence.

Complementary addressed modification of double-stranded DNA within a ternary complex

Double‐stranded DNA containing a d(pG)18·d(pC)18 sequence was shown to be selectively alkylated in the vicinity of this fragment using the 5′‐p‐(N‐2‐chloroethyl‐N‐methylamino)benzylamide of deoxyribooligocytidylate, CIRCH2NH(pdC) n (n = 9, 15), in conditions favouring triple‐stranded complex formation.

N-(2-Hydroxyethyl)phenazinium derivatives of oligonucleotides as effectors of the sequence-specific modification of nucleic acids with reactive oligonucleotide derivatives

It has been found that mono‐ and especially diphenazinium derivatives of oligonucleotides complementary to the DNA sequence adjacent to the target sequence of the addressed alkylation of DNA, significantly enhance the extent and specificity of alkylation with p‐(N‐2‐chloroethyl‐N‐methylamino)benzylamide derivatives of the addressing oligonucleotides, thus playing the role of effector of the sequence‐specific (complementary addressed) modification.

Branched Polyethylene Glycol (Bpeg) Conjugated Antisense Oligonucleotides

Abstract The synthesis of new oligonucleotide conjugates bearing an high molecular weight, branched polyethylene glycol (bPEG) chain is reported.

Design of Functional Diversity in Oligonucleotides via Zwitter-Ionic Derivatives of Deprotected Oligonucleotides

Abstract In this work a number of new designed mono- and bifunctional derivatives of oligonucleotides (deoxyribo-, ribo-series, and their 2′-O-methyl-, P-ethyl, methylphosphonate, and thiophosphate analogs) is described including those bearing reactive, stabilizing, and hydrophobic groups. New approach based on the use of cooperative tandems of short oligonucleotide derivatives is suggested to enhance the selective recognition of nucleic acids.

Antisense activity of an anti-HIV oligonucleotide conjugated to linear and branched high molecular weight polyethylene glycols☆

An anti-HIV 12mer oligonucleotide (ODN) conjugated to two different high molecular weight monomethoxy polyethylene glycols (MPEGs) has been tested for its antisense activity. The capacity of these conjugates to protect the MT-4 cells against HIV infection has been compared to the unmodified, native ODN, and the effect of the different structures of the supporting polymer has been discussed. It was found that only the ODN conjugated to the linear MPEG shows an anti-HIV activity in the investigated conditions. The same 12mer, when conjugated to a branched (MPEG)2, is fully inactive, as well as the native, unmodified ODN.

Porphyrin-linked oligonucleotides Synthesis and sequence-specific modification of ssDNA

Oligonucleotide derivatives bearing hemin and deuterohemin groups were synthesized. The derivatives efficiently react with the complementary nucleotide sequence in ssDNA forming covalent adducts and piperidine‐labile sites. In the case of the deuterohemin derivative, some direct cleavage of the target DNA occurs.

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 TiO2·PL-DNA nanocomposites (polylysine-containing DNA fragments noncovalently immobilized onto TiO2 nanoparticles capable of transferring DNA). These nanocomposites were used for inhibition of human influenza A (H3N2) virus replication in infected MDCK cells. They showed a low toxicity (TC50 ≈ 1800 μg/ml) and a high antiviral activity (>99.9% inhibition of the virus replication). The specificity factor (antisense effect) appeared to depend on the delivery system of DNA fragments. This factor for nanocomposites is ten-times higher than for DNA in the presence of lipofectamine. IC50 for nanocomposites was estimated to be 1.5 μg/ml (30 nM for DNA), so its selectivity index was calculated as ~1200. Thus, the proposed nanocomposites are prospective for therapeutic application.

Interaction of cholesterol-conjugated alkylating oligonucleotide derivatives with cellular biopolymers.

Interactions of oligonucleotide derivatives with mammalian cells and cellular biopolymers have been investigated. The derivatives were oligonucleotides bearing an alkylating 2‐chloroethylamino group at the 3′‐end and a cholesterol residue at the 5′‐terminal phosphate. These compounds are readily taken up by cells and react with cellular DNA, RNA and some proteins which may play a role in delivery of the compounds into cells.

BIOLOGICAL PROPERTIES OF ANTISENSE OLIGONUCLEOTIDES CONJUGATED TO DIFFERENT HIGH-MOLECULAR MASS POLY(ETHYLEN GLYCOLS)

Abstract The effect of the different structures of high-molecular weight poly(ethylen glycol) chains on the biological properties of the conjugated antisense oligonucleotide has been investigated and compared.