Rapid chemical synthesis and circular dichroism properties of some 2′-5′-linked oligoriboadenylates

Markham, A.F.; Porter, Richard A.; Gait, Michael J.; Sheppard, R. C.; Kerr, Ian M.

doi:10.1093/nar/6.7.2569

Cited by 23 publications

(2 citation statements)

References 20 publications

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“…Molar extinction coefficients at 260 nm were taken as 25,800 for dimer, 36,000 for trimer, 41,600 for tetramer, and 50,000 for pentamer according to reported data (12,15,16) and our own measurements of hyperchromicity shifts during phosphodiesterase digestion.…”

Section: Methodsmentioning

confidence: 99%

Monoclonal antibodies to 5'-triphospho-(2'-5')adenyladenosine oligonucleotides.

Cailla¹,

Kaouël²,

Roux³

et al. 1982

Proc. Natl. Acad. Sci. U.S.A.

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Thirteen monoclonal antibodies to ppp(A2'p5')nA oligonucleotides have been produced by fusing Y3 myeloma cells with spleen cells of rat hyperimmunized with A2'p5'A succinyl albumin as immunogen. 125I-labeled A2'p5'A succinyl tyrosine methyl ester was used as a labeled probe. Antibodies were detected by their ability to bind the labeled analog and were selected for their affinity for A2'p5'A. There were no significant differences between the properties of the monoclonal antibodies and of the antiserum. They discriminated between 2'-5' and 3'-5' phosphodiester bonds: they crossreacted poorly with (A3'p5')2A (crossreactivity ratio, greater than 10(4)) and even less with ATP an adenosine (crossreactivity ratio, greater than (6)). The affinity was high (Kd = 6 x 10(-12) M) for succinyl A2'p5'A, which is the best ligand, and also high for A2'p5'A (crossreactivity ratio, 3) and (A2'p5')2A, (A2'p5')3A, and (As'p5')4A (crossreactivity ratio, 7.5). The binding to triphosphorylated isomers, ppp(A2'p5)nA, was affected by the presence of the triphosphate groups, and the affinity increased as the length of the isomer increased (crossreactivity ratio, 10,000 for n = 1 to 200 for n = 4). Thermodynamic analysis of these data demonstrated that, in dephosphorylated isomers, the binding site of highest affinity was located at the 5'-OH end of the molecule whereas in phosphorylated isomers, the favorable binding sites were in the middle and at the 2'-OH end of the chain. Use of monoclonal antibodies of such a specificity together with the 125I-labeled 2-5A analog allows quantification of (A2'p5')nA directly and of ppp(A2'p5')nA after removal of the terminal phosphates by alkaline phosphatase treatment.

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Section: Methodsmentioning

confidence: 99%

Monoclonal antibodies to 5'-triphospho-(2'-5')adenyladenosine oligonucleotides.

Cailla¹,

Kaouël²,

Roux³

et al. 1982

Proc. Natl. Acad. Sci. U.S.A.

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“…This effect, however, is only transitory, since the 2'-5'A molecules are rapidly cleaved by cellular phosphodiesterases [lo] leading to loss of antiviral activity. In order to suppress the digestion of the 2'-5'A oligomers, several synthetic modifications of the native structure were accomplished at the aglycone [ll-201, the sugar [21-371, and the phosphate moiety [38][39][40][41][42][43][44][45]. It is well established, mainly due to the pioneering work of Eckstein [46], that phosphorothioate analogues of oligonucleotides are valuable models to study certain stereochemical aspects of enzyme-catalyzed phosphoryl and nucleotidyl transfer reactions.…”

mentioning

confidence: 99%

Nucleotides. Part XXXVIII.. Syntheses and characterization of phosphorothioate analogues of (2′–5′) adenylate dimer and trimer and their 5′‐O‐monophosphates

Charubala

Pfleiderer

1992

Helvetica Chimica Acta

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Dedicated to Prof. Dr. Wilhelm Fleischhacker on the occasion of his 60th birthday (8.X1.91) ~ ~~The chemical syntheses of the phosphorothioate of (2'-5')adenylate dimer (see 6a, 6b) and trimer (see 1 la, 1 lb, 12a, 12b) as well as of their 5'-monophosphates (see 15a, 15b, 16a, 16b) using the phosphoramidite method are described. The resulting diastereoisomer mixtures were separated into the pure components by chromatographical means. All synthetic intermediates were characterized by TLC, elemental analysis, and UV and 'H-NMR spectra.1. Introduction. -Establishment of an antiviral state in cells results from a multitude of biochemical changes induced by interferons and involving several proteins in a cascade of reactions [2-41. One of the proteins is the enzyme 2'-5'A synthetase, which is activated upon binding to double-stranded RNA [5] and converts then ATP into a series of (2'-5')-linked adenylate oligonucleotides containing a 5'-terminal triphosphate function [6]. Such oligomers carrying a 5'-di-or 5'-triphosphate and consisting of three or more monomer units bind to, and subsequently reversibly activate, an endogenous or sometimes interferon-induced endoribonuclease [7] [8]. The activated endoribonuclease, RNase L, cleaves then messenger and ribosomal RNA's [9], resulting in inhibition of translation. This effect, however, is only transitory, since the 2'-5'A molecules are rapidly cleaved by cellular phosphodiesterases [lo] leading to loss of antiviral activity. In order to suppress the digestion of the 2'-5'A oligomers, several synthetic modifications of the native structure were accomplished at the aglycone [ll-201, the sugar [21-371, and the phosphate moiety [38][39][40][41][42][43][44][45]. It is well established, mainly due to the pioneering work of Eckstein [46], that phosphorothioate analogues of oligonucleotides are valuable models to study certain stereochemical aspects of enzyme-catalyzed phosphoryl and nucleotidyl transfer reactions.The first synthesis of phosphorothioate analogues of (2'-5')oligoadenylates were performed by Nelson, Bach, and Verheyden [42] applying the phosphite triester approach in conjunction with sulfur oxidation. Formation of chiral phosphorothioate functions led to diastereoisomeric mixtures of which the dimer cores could be separated chromato-

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Conformational and stacking properties of 3′-5′ and 2′-5′ linked oligoribonucleotides studied by CD

et al. 1998

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Comparative CD studies have been carried out to characterize the properties of 2′–5′ and 3′–5′ oligoriboadenylates and oligoribouridylates from dimer to decamer. The CD band of the 3′–5′ oligoribonucleotides was larger than that of the 2′–5′ oligoribonucleotides and increased with the increase in chain length, while the CD band of the 2′–5′ oligoribonucleotides increased little beyond the dimer level. The CD analysis of the chain length dependency revealed that the 3′–5′ oligoribonucleotides adopt mainly the base‐base stacking interaction, while the base‐sugar interaction is predominant in the 2′–5′ oligoribonucleotides. The CD intensity of 3′–5′ oligoribonucleotides decreased to a larger extent at elevated temperatures or in the presence of ethanol compared to that of the 2′–5′ counterparts. Mg2+ or Mn2+ ion enhanced the magnitude of the CD of 3′–5′ octariboadenylate, while a small decrease in the CD was observed by the presence of Mg2+ or Mn2+ ion to the 2′–5′ octariboadenylate. The 3′–5′ oligoribonucleotide is likely conformationally flexible and can form helical ordered structure with strong base‐base stacking depending on changes in the environment such as temperature, the presence of Mg2+ ion, or hydrophobicity of the solution. © 1996 John Wiley & Sons, Inc.

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Rapid chemical synthesis and circular dichroism properties of some 2′-5′-linked oligoriboadenylates

Cited by 23 publications

References 20 publications

Monoclonal antibodies to 5'-triphospho-(2'-5')adenyladenosine oligonucleotides.

Monoclonal antibodies to 5'-triphospho-(2'-5')adenyladenosine oligonucleotides.

Nucleotides. Part XXXVIII.. Syntheses and characterization of phosphorothioate analogues of (2′–5′) adenylate dimer and trimer and their 5′‐O‐monophosphates

Conformational and stacking properties of 3′-5′ and 2′-5′ linked oligoribonucleotides studied by CD

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