Antiviral resistance by the polyinosinic acid-poly (1-vinylcytosine) complex.

The antiviral activities of analogs of the double-stranded complex of polyinosinic and polycytidylic acids [poly(I).poly(C)], which is a potent interferon inducer, have been studied. Structural changes that modify the polymer backbone substantially, such as loops or 2' --> 5' phosphodiester bonds, lead to decreased antiviral activity. Unexpectedly, however, the complex of polyinosinic acid and poly(1-vinylcytosine), which is only a much more distantly related analog of poly(I) . poly(C), shows high activity. It is postulated that the high activity is related to the reduction of the charge/mass ratio and to the existence of this complex in an aggregated state; these are two factors that generally enhance the uptake of compo unds by cells.

Synthesis of polynucleotide analogs containing a polyvinyl alcohol backbone.

Water soluble homo-base polynucleotide analogues were synthesized in which polyvinyl alcohol and partially phosphonated polyvinyl alcohol constituted the backbones,onto which were grafted uracil or adenine via 1,3-dioxane spacers formed by acetal formation with the 1,3-diol moieties in PVA. The resulting adenine-PVA polynucleotide analogs exhibited hyperchromic effects, which was not the case for the corresponding uracil compounds. Mixtures of the adenine- and aracil PVA-phosphate polynucleotide analogs in solutions exhibited characteristic S-shaped UV-absorbance vs temperature and melting curves with melting points at approximately 40 degrees C.

A rapid ELISA for measurement of antibodies to nucleic acid antigens using UV-treated polystyrene microplates.

Pretreatment of polystyrene microplate wells with certain doses of UV light enhances their capacity for binding to single-stranded DNA, double stranded DNA and various synthetic polynucleotides. The use of UV-irradiated plates to immobilize nucleic acid antigens provides a simple, rapid, and specific ELISA for measuring anti-nucleic acid antibodies. The assay is at least as sensitive as the more complex method of precoating plates with poly(L-lysine). It is useful for detection of anti-DNA antibodies in sera of systemic lupus erythematous patients, as well as in culture fluids of murine and human anti-DNA-secreting hybridomas.

Antiviral amphipathic oligo- and polyribonucleotides: analogue development and biological studies.

A series of novel N1 alkylated purine nucleic acids were polymerized either enzymatically or by automated synthesis to further establish the SAR requirements for HIV, RT, and HCMV activity. Out of the series, two constructs, 2'-O-methyl-1-allylinosinic acid phosphorothioate 33-mer (16) and an oligomer incorporating 1-propyl-6-thioinosinic acid residues (20), were found to be highly active under all three assay conditions. SAR studies indicate that sulfur incorporation, high molecular weight, and low steric bulk at N1 all can be important for activity.

Polynucleotide analogues. Copolymers of vinyl bases with acrylic acid, methylacrylic acid, acrylamide, and 1-vinylpyrrolidone.

Preliminary studies are reported on the synthesis and testing of substituted vinyl polymers that are designed to have sequence specific affinity for polyribonucleic acids. Copolymers of 1-vinyluracil with acrylic acid, 2-methylacrylic acid, or 1-vinyl-2-pyrrolidone were prepared by gamma-irradiation to give the respective polymers 1,3, and 4. Similarly, 9-vinyladenine yielded copolymeric products 5 and 6 with acrylic acid or 2-methylacrylic acid. Radical initiated polymerization of 9-vinyladenine with acrylamide yielded copolymer 7. The products were characterized by elemental analysis and ultraviolet, infrared, and nuclear magnetic resonance spectroscopy. No hypochromicity could be detected on mixing polymers 1-4 with poly(adenylic acid). The acrylic acid copolymer 2 containing a high ratio of vinyluracil was a potent inhibitor of poly(adenylic acid) coded polylysine synthesis in an in vitro system. Polymers 6 and 7, containing a high proportion of vinyladenine, inhibited poly(uridylic acid) coded poly(phenylalanine) synthesis.

[Interaction of natural and synthetic polynucleotides with liposomes in the presence of divalent cations]. / Vzaimodeistvie prirodnykh i sinteticheskikh polinukleotidov s liposomami v prisutstvii dvukhvalentnykh kationov.

The formation of complexes of polynucleotides (DNA, poly A.poly U) with liposomes from egg lecithins, L-alpha-phosphatidylcholine, dimirystoyl and other lipids in the presence of divalent cations was studied by differential scanning microcalorimetry circular dichroism and turbidimetry. It was shown that the secondary structure of polynucleotides (double or triple helix) was necessary for the formation of these complexes. This structure was partially destroyed during formation of complexes. It was shown, that three main types of lipids, i.e. phosphatidylcholine, phosphatidylethanolamine and sphingomyelin participate in interactions between liposomes, polynucleotides and Mg2+.

Synthetic analogues of polynucleotides. (Part) XIV. The synthesis of poly (3'-0-carboxymethyl-2'-deoxycytidine) and its interaction with polyinosinic acid.

Poly (3'-O-carboxymethyl-2'-deoxyctidine) (VII) has been synthesised by the polymerisation of 3'-O-carboxymethyl-4-N-phenoxyacety-2'-deoxycytidine (V) and removal of the phenoxyacetyl groups under acidic conditions. V was obtained by the action of 2,4-dinitrophenyl phenylacetate on 3'-O-carboxymethyl-5'-O-triphenylmethyl-2'-deoxycytidine (III) followed by removal of the triphenylmethyl group under carefully controlled acidic conditions. The polymer, VII gave a hypochromic effect of about 20% at 250nm when mixed with poly (1) in 0.2Macetate, pH 5.0. It appeared, therefore, that a complex was formed. Upon heating a solution of this complex there was an initial decrease in optical density followed by a much larger increase to give a Tm of about 60 degrees. Attempts to form the 3'-O-carboxymethyl derivative of 4-N-phenoxyacetyl-5'-O-'triphenylmethyl-2'-deoxycytidine to give a shorter synthetic route to VII were not successful. 3'-O-Carboxymethyl-2'-deoxycytidine was obtained by removal of thetriphenylmethyl group from III. Attempts to polymerise this compound in concentrated aqueous solution with a water-soluble carbodiimide were not successful.

Some acyclic analogues of nucleotides and their template-directed reactions.

Bismonophosphoimidazolides of acyclic analogues of guanosine IV and adenosine V were synthesized. They undergo oligomerization in the presence of complementary polynucleotide templates. Details of their synthesis and their subsequent template- and nontemplate-directed reactions are described, and their possible relevance to the origin of life is discussed.

Enzyme screening with synthetic multifunctional pores: focus on biopolymers.

This report demonstrates that a single set of identical synthetic multifunctional pores can detect the activity of many different enzymes. Enzymes catalyzing either synthesis or degradation of DNA (exonuclease III or polymerase I), RNA (RNase A), polysaccharides (heparinase I, hyaluronidase, and galactosyltransferase), and proteins (papain, ficin, elastase, subtilisin, and pronase) are selected to exemplify this key characteristic of synthetic multifunctional pore sensors. Because anionic, cationic, and neutral substrates can gain access to the interior of complementarily functionalized pores, such pores can be the basis for very user-friendly screening of a broad range of enzymes.