We have synthesized the tetradecamer GAGCXGATAACAAG containing a part of the sequence of the lactose operator. A guanine base in the sequence is replaced by the adduct of the carcinogen 2-acetylaminofluorene with guanine. Under the standard conditions of de-protection, the fluorene moiety is lost, leaving behind a guanine oxidation product. New conditions of de-protection have been developed wh...

The method presented here enables the isolation of three monofunctional adducts. These are: platination of cytosine, adenine and guanosine. The three detected bifunctional complexes were: guanine N7 to N7, adenine N7 to N7 and adenine N7 to N1. A mixed bifunctional complex of guanine and adenosine and the product of polymerization of three adenines and two moieties of cis DDP were also detected...

Synthetic homopolyribonucleotides poly(A), poly(U), poly(C), and poly(G), poly(A, G, U), apurinic acid and native and denatured DNA from calf thymus were analyzed by means of cyclic voltammetry (CV) using a hanging mercury drop electrode. It was shown that guanine containing polynucleotides, i.e. poly(G), poly(A, G, U) and DNA yield an anodic peak of guanine in the vicinity of a potential of -0...

Graphene oxide nanoplatelets (GONPs) with extremely sharp edges (lateral dimensions ∼ 20-200 nm and thicknesses <2 nm) were applied in extraction of the overexpressed guanine synthesized in the cytoplasm of leukemia cells. The blood serums containing the extracted guanine were used in differential pulse voltammetry (DPV) with reduced graphene oxide nanowall (rGONW) electrodes to develop fast an...

The serotonin1A (5-HT1A) receptor is an important member of the superfamily of seven transmembrane domain G-protein coupled receptors (GPCRs). We report here that guanine nucleotide sensitivity of agonist binding to hippocampal 5-HT1A receptors is dependent on the concentration of Mg2+. Our results show that agonist binding to 5-HT1A receptors is relatively insensitive to guanine nucleotides in...

One-electron oxidized guanine is an important reactive intermediate in the formation of oxidatively generated damage in DNA and a variety of methods have been utilized for the abstraction of a single electron from the guanine moiety. In this study, an alternative approach for the site specific, independent generation of the guanine radical, utilizing N-hydroxypyrid-2(1H)-one as a photolabile mo...

The effects of guanine nucleotides on binding of 8-cyclopentyl-1,3-[3H]dipropylxanthine ([3H]DPCPX), a highly selective A1 adenosine receptor antagonist, have been investigated in rat brain membranes and solubilized A1 receptors. GTP, which induces uncoupling of receptors from guanine nucleotide binding proteins, increased binding of [3H]DPCPX in a concentration-dependent manner. The rank order...

Aside from a double helix, deoxyribonucleic acid (DNA) folds into non-canonical structures, one of which is the guanine quadruplex. Cationic porphyrins bind guanine quadruplexes, but the effects of ligand binding on the structure of guanine quadruplexes with more than four contiguous guanine quartets remains to be fully elucidated. Double electron-electron resonance (DEER) spectroscopy conducte...

An assay procedure, utilizing high pressure liquid chromatography, has been designed which allows both reactions catalyzed by hypoxanthine-guanine phosphoribosyltransferase to be monitored simultaneously. Using this procedure and the theories described by Huang (Huang, C. V. (1979) Methods. Enzymol. 63, 486-500) for alternate substrate kinetic analysis, we have determined that purified hypoxant...

Abstract SERS spectroscopy is successfully employed in this work to reveal different components integrating the cochineal colorant for dying archaeological textile samples from Arica Region North Chile. This analysis was done by in-situ experiments that does not imply material (colorant and biomolecules) extraction. The spectroscopic of textiles reveals presence bands attributed carminic acid n...