The voltammetric behaviour of the purine base guanine and the corresponding n,.,c!eoside guanosine at a glaxgy carbon ek~rode was investigated with the help of ultrasound. The adsorption of guanine and guanosiae as well as the adsorption of tJieir ox~Kion pf~:gh~ affects the overall voltammetric characteristics dramatically. In particular, the effect of ultrasound on the simultaneous adsoq~aa o...

Modified nucleobase analogues can serve as powerful tools for changing physicochemical and biological properties of DNA or RNA. Guanosine derivatives containing bulky substituents at 8 position are known to adopt syn conformation of N-glycoside bond. On the contrary, in RNA the anti conformation is predominant in Watson-Crick base pairing. In this paper two 8-substituted guanosine derivatives, ...

A facile method for the introduction of various substituents at the C-6 position of guanosine and 2'-deoxyguanosine is reported. In a simple, 1-step transformation, tert-butyldimethylsilyl protected guanosine and 2'-deoxyguanosine were converted to the O(6)-(benzotriazol-1-yl) derivatives via reaction with 1H-benzotriazol-1-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP) and 1,8-...

The present studies were undertaken to determine the mechanism by which attachment of the carcinogen N-2-acetylaminofluorene to guanosine residues in nucleic acids distors their structure and function. Oligonucleotides were modified with N-acetoxy-2-acetylaminofluorene, repurified, and their base compositions analyzed. Evidence is presented that acetylaminofluorene residues bound to guanosines ...

Several laboratories have reported studies on individual enzymes that belong to the general class of adenosine triphosphate : nucleoside monophosphate phosphotransferases (EC 2.7.4.4), commonly termed nucleoside monophosphate kinases (l-7). Studies with partially purified enzyme preparations have indicated that a variety of nucleoside monophosphates can serve as alternative substrates for nucle...

The specific binding of vasoactive intestinal peptide (VIP) to bovine thyroid plasma membranes is inhibited by guanine nucleotides. Guanosine 5'-triphosphate (GTP) and the non-hydrolyzable GTP analogs guanosine 5'-beta,gamma-imidotriphosphate (Gpp(NH)p) and guanosine 5'-O-(3-thiotriphosphate) (GTP-gamma-S) inhibited markedly the binding of VIP to its receptors. This inhibition was higher with G...

[structure: see text] A series of receptors (11-16) designed to simultaneously bind the Watson-Crick and Hoogsteen sites of guanosine were synthesized, and their binding of guanosine tri-O-pentanoate (32) was probed via 1H NMR complexation studies in 5% DMSO-d6-chloroform-d. The guanosine receptors were synthesized with aminonaphthalene or aminoquinoline auxiliary groups tethered to N-4 of cyto...

Ribavirin is a guanosine ribonucleoside analog that displays broad-spectrum anti-viral activity and is currently used for the treatment of some viral infections. Ribavirin has recently been proposed to also be a mimic of the 7-methyl guanosine cap found at the 5' end of mRNAs. To obtain supporting functional data for this hypothesis, we assessed the ability of ribavirin triphosphate to interfer...

Using systematic evolution of ligands by exponential enrichment (SELEX), an RNA molecule was isolated that displays a 1,000-fold higher affinity for guanosine residues that carry an N-7 methyl group than for nonmethylated guanosine residues. The methylated guanosine residue closely resembles the 5' terminal cap structure present on all eukaryotic mRNA molecules. The cap-binding RNA specifically...