Oligoadenylic Acid Research Articles

Synthesis of adenylyl-(3',5')-nucleosides, adenylyl-(3',5')-guanosine 2',3'-cyclic phosphate, and oligoadenylic acids by ribonuclease U2.

Synthesis of adenylyl-(3',5')-nucleosides, adenylyl-(3',5')-guanosine 2',3'-cyclic phosphate, and oligoadenylic acids by ribonuclease U2.

A Kinetic Analysis of the Phosphorolysis of Oligonucleotides by Polynucleotide Phosphorylase

Abstract The kinetics of the phosphorolysis of oligoadenylic acids by highly purified polynucleotide phosphorylase of Micrococcus luteus have been investigated in detail. Double reciprocal plots of initial velocity against either inorganic phosphate or oligonucleotide substrate concentration were linear, and further, the affinity of the enzyme for either substrate was unaffected by the presence of the other. Oligonucleotides with phosphate esterified to the free terminal 3'-OH groups are competitive inhibitors with respect to oligonucleotide substrate and noncompetitive with respect to inorganic phosphate. Conversely, two analogues of the ADP product, dADP and adenosine 5'-methylene diphosphonate, are competitive inhibitors with respect to Pi and are, in general, noncompetitive with respect to oligonucleotide. The results were almost identical with primer-independent and primer-dependent enzyme. On the basis of these data a rapid equilibrium random Bi-Bi kinetic mechanism is proposed for M. luteus polynucleotide phosphorylase. The stepwise phosphorolysis of oligonucleotides with chain length up to six proceeds by a random mechanism and not by the processive mechanism observed with long polymers.

Étude par luminescence des interactions dans les acides oligo et polyadényliques

Luminescence study of interactions in oligo- and polyadenylic acids Interactions between the bases of oligoadenylic acids (A n) lead to a red shift of both the fluorescence and the phosphorescence spectra at 77° K in a water-propylene glycol mixture (1:1, v v ). These shifts depend on the number n of adenine residues in the oligomer as well as on the nature of the phosphodiester linkage (2′–5′ or 3′–5′). The luminescence of copolymers containing adenosine and cytidine and of complexes of poly A with oligo U or poly U has also been studied. The fluorescence of poly A nC, where n is the ratio of the number of A and C residues in the copolymer is of the excimer type for n = 1 (as observed in the dinucleotides ApC or CpA) and similar to that of poly A for n = 6.5. Oligomers containing m adenosine residues and one terminal cytidine have been obtained from pancreatic ribonuclease digestion of copoly A nC with n = 6.5. The fluorescence of these oligomers is like that of the corresponding oligo A m even for the smallest value of m (m = 5). Oligo U 10 quenches the fluorescence of poly A as does poly U. The quenching is linearly related to the amount of oligo U 10 linked by hydrogen bonds to the poly A. No evidence of energy transfer at the singlet level in poly A could be obtained. The luminescent properties and results obtained from other physical methods are discussed in relation with the possible existence of a weak transition on the long wavelength side of the main ultraviolet absorption band of adenosine.

Oligonucleotide interactions. I. Structure of 2:1 complexes between polyuridylic acid and oligoadenylic acid.

AbstractThe circular dichroism of a number of 1:2 complexes between oligoadenylic acid and polyuridylic acid has been measured. The structure of these complexes, as evidenced by their optical properties, is independent of the chain length of the oligonucleotide throughout all ranges of chain lengths from adenosine to high molecular weight polyadenylic acid. A similar structure was found for the complex (Ap)5A:2(Up)5U.

The phosphorylation of 5'-oligoadenylic acids by adenylate kinase and adenosine triphosphate.

1. Radioactivity was incorporated into 5'-O-phosphoryladenylyl-(3'-5')-adenosine (pApA) on incubation with adenylate kinase and [gamma-(32)P]ATP. The corresponding triadenylate and tetra-adenylate reacted more slowly. 2. Only oligoadenylate with a terminal 5'-phosphate served as the substrate. 3. The product formed from pApA was shown to behave like 5'-O-pyrophosphoryladenylyl-(3'-5')-adenosine (ppApA) on hydrolysis with alkaline phosphatase, potassium hydroxide and hydrochloric acid. 4. The characteristics of the reaction indicated that it was catalysed by adenylate kinase, but the rate of phosphate transfer from ATP to pApA was about 0.01% of that in the typical reaction with AMP. 5. The reverse reaction between ADP and ppApA occurred readily, but no additional phosphorylation of ppApA (to give pppApA) could be demonstrated.

The Stability of Oligoadenylate-Polyuridylate Complexes As Measured by Thermal Chromatography

Abstract The complexes of defined oligoadenylic acids with polyuridylic acid have been investigated by observing their release from hydroxylapatite columns as a function of temperature. The temperature of release is a function of the chain length of the oligonucleotide, the presence of Mg++ ion, and the presence or absence of terminal phosphates on the oligonucleotide. This method provides a convenient way of characterizing the thermal stability of trace amounts or labeled oligonucleotide-polynucleotide complexes.

Optical rotatory dispersion of oligoadenylic acids and a consideration of the factors stabilizing helical polynucleotides.

Optical Rotatory Dispersion of Oligoadenylic Acids and a consideration of the Factors Stabilizing Helical Polynucleotides1

Thermodynamics of the Helix-Coil Equilibrium in Oligoadenylic Acid from Hypochromicity Studies

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThermodynamics of the Helix-Coil Equilibrium in Oligoadenylic Acid from Hypochromicity StudiesJon Applequist and Vinayak DamleCite this: J. Am. Chem. Soc. 1965, 87, 7, 1450–1458Publication Date (Print):April 1, 1965Publication History Published online1 May 2002Published inissue 1 April 1965https://doi.org/10.1021/ja01085a007RIGHTS & PERMISSIONSArticle Views243Altmetric-Citations146LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (989 KB) Get e-Alerts Get e-Alerts

The acid-base properties of ribonucleic acid. II. Spectrophotometric titration studies of poly-AU.

The ultraviolet-absorption spectrum of synthetic oligoadenylic acid was studied at different pH values over the range 20–80°. The changes noted were qualitatively similar to those reported for polyadenylic acid. It is inferred from these observations that oligoadenylic acid, like polyadenylic acid, may form stable ordered structures in acidic solutions. The ultraviolet-absorption spectrum of a copolymer of adenylic acid and uridylic acid (AMP/UMP = 1.5) was also found to depend upon pH, and temperature. The changes in the spectrum suggest that in neutral 0.1 M sodium phosphate at 25° the copolymer has an organized secondary structure stabilized by interaction between adenine and uracil residues. In solutions of pH 4.0 or less the spectrum of the copolymer was found to depend on temperature in the manner noted for oligoadenylic acid suggesting that ordered domains, comparable with oligoadenylic acid at the same pH, were formed. The phase diagram deduced for the copolymer was found to be analogous to that reported for the system poly-A plus poly-U.

The acid-base properties of ribonucleic acid

The ultraviolet-absorption spectrum of synthetic oligoadenylic acid was studied at different pH values over the range 20–80°. The changes noted were qualitatively similar to those reported for polyadenylic acid. It is inferred from these observations that oligoadenylic acid, like polyadenylic acid, may form stable ordered structures in acidic solutions. The ultraviolet-absorption spectrum of a copolymer of adenylic acid and uridylic acid (AMP/UMP = 1.5) was also found to depend upon pH, and temperature. The changes in the spectrum suggest that in neutral 0.1 M sodium phosphate at 25° the copolymer has an organized secondary structure stabilized by interaction between adenine and uracil residues. In solutions of pH 4.0 or less the spectrum of the copolymer was found to depend on temperature in the manner noted for oligoadenylic acid suggesting that ordered domains, comparable with oligoadenylic acid at the same pH, were formed. The phase diagram deduced for the copolymer was found to be analogous to that reported for the system poly-A plus poly-U.

The acid-base properties of ribonucleic acid II. Spectrophotometric titration studies of poly-AU

The ultraviolet-absorption spectrum of synthetic oligoadenylic acid was studied at different pH values over the range 20–80°. The changes noted were qualitatively similar to those reported for polyadenylic acid. It is inferred from these observations that oligoadenylic acid, like polyadenylic acid, may form stable ordered structures in acidic solutions. The ultraviolet-absorption spectrum of a copolymer of adenylic acid and uridylic acid (AMP/UMP = 1.5) was also found to depend upon pH, and temperature. The changes in the spectrum suggest that in neutral 0.1 M sodium phosphate at 25° the copolymer has an organized secondary structure stabilized by interaction between adenine and uracil residues. In solutions of pH 4.0 or less the spectrum of the copolymer was found to depend on temperature in the manner noted for oligoadenylic acid suggesting that ordered domains, comparable with oligoadenylic acid at the same pH, were formed. The phase diagram deduced for the copolymer was found to be analogous to that reported for the system poly-A plus poly-U.