Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Polyribonucleotides”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMedDate not supplied

[Segmental flexibility of single-, double-, and triple-stranded polyribonucleotides from the data of spin label method. Formation of the triple-stranded poly(A.A.U) polynucleotide helix].

Segmental mobility dynamic peculiarities of poly(U), poly(A) and poly(C) synthetic polymers and their complexes were investigated by spin-label method. Imidazolide spin-label was introduced into 2'-oxi-groups of polymer ribose in correlation: one spin-label on 18-20 bases. Formation of complexes was observed by ESR spectra at two pH: 4.2 and 7.2. Segmental mobility of only single strand spin-labelled polymer segment and in the complex was evaluated by measuring rotational correlation time (tau) determined by dependence of distances between outer wide extrema in ESR spectra from solvent viscosity at different temperatures. It turned out that correlation time tau of single strand structures in a high degree depend on pH and temperature. For three strand structures abrupt increase of tau because of appearance of rigidity was observed. It is possible to evaluate part of triple complexes poly(U.A.A) and poly(U.U.A) existing in dynamic equilibrium depending on pH and temperature by the form of outer wide extrema. Adding of dye to complex of poly(U).poly(A) causes an increase of rigidity of the supermolecular structure. Quantitative characteristics of formed complexes were obtained by simulation of ESR spectra on computer.

Electron Spin Resonance Spectroscopy↗
PubMed1979

Genetic and biochemical evidence for the involvement of a bacterial component in the mitogenic properties of polyribonucleotides on murine B lymphocytes.

The mitogenic response of C3H/HeJ mice to the B cell mitogens, poly C and poly I, is approximately one-half the response measured in various LPS-responder strains. C3H/HeJ mice respond normally to poly I:C, the heteroduplex polymer. The low responder phenotype of C3H/HeJ mice to poly C and poly I is shown by an analysis of (C3H/HeJ x C57BL/6J-By-Ps)F1 X C3H/HeJ backcross progeny to result from a gene locus that is closely linked or identical to the defective LPS response locus expressed by the C3H/HeJ strain. The entire mitogenic activity in poly C preparations and most of the mitogenic activity in poly I preparations is insensitive to ribonuclease degradation. Hot aqueous phenol extraction of the polynucleotides separates the majority of the mitogenic activity that is soluble in the combined interface and phenol phase fraction from the aqueous soluble polynucleotides. The ribonuclease-insensitive, phenolsoluble contaminant elicits a reduced response in C3H/HeJ mice as compared to an LPS responder strain. We conclude that 1) poly C has no inherent mitogenic activity; 2) poly I preparations contain both ribonucleasesensitive and insensitive mitogenic activities; 3) the ribonuclease-resistant mitogenic activity in polynucleotide preparations has properties unlike those of LPS or lipid A; and 4) the product of LPS response gene has an effect upon the mitogenic stimulation of spleen cells by the contaminant.

Animals↗
PubMed1988

Proton magnetic resonance studies of the binding of oligopeptides containing tryptophan to polyribonucleotides poly A, poly U and poly C.

The binding of oligopeptides Lys-Trp-Gly-Lys OtBu, Lys-Gly-Trp-Lys OtBu and Lys-Trp-Lys to Polyadenylic, Polycytidylic and Polyuridylic acid has been studied by Proton NMR at 90 MHz and 500 MHz at oligopeptide/Polynucleotide ratios ranging from 0.01 to 0.20 at 275-365 K. Downfield shift of 0.01-0.2 ppm at 296 K of the H2, H8 and H1' resonances of Poly A due to binding with oligopeptides is accompanied by a marked narrowing of resonance lines of Poly A. The ring protons of tryptophan shift upfield by 0.3-0.6 ppm at 296 K on binding to Poly A. Changes in chemical shift of both adenine and tryptophan protons on binding are much smaller at 355 K than that at 275 K. These observations are ascribed to intercalation of the tryptophan ring in the adenine bases resulting in partial destacking of adenine bases in Poly A. Using the magnetic anisotropy ring current shifts, an overlap geometry of tryptophan ring in the adenine has been proposed. Addition of oligopeptides to Poly C and Poly U, on the other hand, suggests that tryptophan ring does not stack in Poly U and Poly C.

Magnetic Resonance Spectroscopy↗
PubMed1985

Immunomodulating effects of synthetic polyribonucleotides.

The polynucleotide complexes are a class of compounds whose activities to date deserve close scrutiny with respect to their potential role as biological response-modifying agents in human disease. The challenge for the future lies in directing and controlling their activity with respect to a single desired effect, such that intelligent interference in patients with immunological aberrancies might occur.

Humans↗