In previous work (McKee EE, Bentley AT, Smith RM Jr, and Ciaccio CE, Biochem Biophys Res Commun 257: 466-472, 1999), the transport of guanine nucleotides into the matrix of intact isolated heart mitochondria was demonstrated. In this study, the time course and mechanisms of guanine nucleotide transport are characterized. Two distinct mechanisms of transport were found to be capable of moving gu...

As a result of the investigations of Kidder and coworkers, it has recently become possible to grow the ciliated prot.oaoan Tetrahymena geleii in a culture medium which is of chemically known composition (1, 2), as well as free of other microorganisms. Interest was aroused by similarities in its requirements for amino acids (2, 3) and vitamins (4) to those of the mammal, although differences hav...

Guanine 7一N-oxide was shown to have synergistic activity in combillation with neplanocin Aagainst a rhabdovirus, infectious hematopoietic necrosis virus (IHNV), as reported previ ously. We examined further the antiviral activity of guanine 7-N-oxide ill comblnation with other nucleoside antibiotics against IHNV. Synergism was seen between guanille 7-N-oxide and D-eritadenine or cordycepin.16s c...

A tetramer quadruplex structure is formed by four parallel strands of DNA/ RNA containing runs of guanine. These quadruplexes are able to form because guanine can Hoogsteen hydrogen bond to other guanines, and a tetrad of guanines can form a stable arrangement. Recently we have discovered that probes on Affymetrix GeneChips that contain runs of guanine do not measure gene expression reliably. W...

In their observations of the electron spin resonance (ESR) of irradiated nucleic acids and their constituents in the powdered form, Shields and Gordy' found a triplet caused by two equally coupling protons in guanine and deoxyguanosine. Later, this was interpreted by Gordy, Pruden, and Snipes2 as arising from a radical formed hy hydrogen addition to the C(8). The interpretation was later proved...

Inosine 5'-monophosphate dehydrogenase (IMPDH) is the critical, rate-limiting enzyme in the de novo biosynthesis pathway for guanine nucleotides. Two separate isoenzymes, designated IMPDH types I and II, contribute to IMPDH activity. An additional pathway salvages guanine through the activity of hypoxanthine-guanine phosphoribosyltransferase (HPRT) to supply the cell with guanine nucleotides. I...

The nonadiabatic decay of the biologically relevant guanine tautomer (9H-guanine) in aqueous solution has been investigated by trajectory surface hopping simulations in a quantum mechanical-molecular mechanical (QM-MM) framework. The QM part (9H-guanine) was treated at the semiempirical OM2/MRCI level, while the MM part (water) was described by the TIP3P force field. The optimized geometries fo...

We have shown previously that induced maturation of the human myeloid leukemia cell line, HL-60, is associated with a selective down-regulation of guanine ribonucleotide synthesis and depletion of intracellular guanosine triphosphate (GTP) and guanosine diphosphate (GDP) pools. We showed, furthermore, that inhibitors of the enzyme, inosine monophosphate (IMP) dehydrogenase, which catalyzes the ...

Misonidazole, after reduction to the hydroxylamine derivative, was found to react with guanosine in aqueous solution at pH 7. The guanosine product was isolated and was assigned a structure having a new 5-membered ring with a -CHOH-CHOH-linkage between the N-1 and N-2 positions of guanine. Removal of the sugar residue from the guanosine product by acid hydrolysis resulted in the corresponding g...