In the course of work now in progress on the determination of constitution of nucleic acid and its primary hydrolytic products-neucleotides and neucleosides-it has finally become necessary to develop and utilize a new method for introducing methyl radicals into pyrimidine and purine combinations. The alkylation methods generally employed for bringing about such changes, namely, by interaction o...

Density functional theory (DFT) calculations were performed to investigate the effects of a carbon nanotube (CNT) on the properties of the fluorouracil (F-Uracil) anticancer drug. To achieve the purpose, a molecular model including both of F-Uracil and CNT molecules was created to represent the CNT@F-Uracil compound. The optimized parameters indicated that the new compound could show new proper...

The six-membered ring of the uracil part of the title compound, C(24)H(28)N(2)O(4), is nearly planar (r.m.s. deviation = 0.013 Å); the aromatic ring of the 3,5-dimethyl-benzyl substitutent is aligned at 85.4 (1)° with respect to this mean plane. The phenyl ring of the substituent at the 1-position takes up two orientations in a 1:1 ratio. In the crystal, two mol-ecules are liked by a pair of N-...

We present an all atom potential energy function for the simulation of proteins and nucleic acids. This work is an extension of the CH united atom function recently presented by S. J. Weiner et al. (J . Amer. Chem. SOC., 106,765 (1984). The parameters of our function are based on calculations on ethane, propane, n-butane, dimethyl ether, methyl ethyl ether, tetrahydrofuran, imidazole, indole, d...

Uracil-DNA glycosylase was partially purified from HeLa cells. Various substrates containing [3H]dUMP residues were prepared by nick-translation of calf thymus DNA. The standard substrate was double-stranded DNA with [3H]dUMP located internally in the chain. Compared to the release of uracil from this substrate, a 3-fold increase in the rate was seen with single-stranded DNA, and a 20-fold redu...

In a previous study, we found that 2-deoxyribonolactone is effectively generated in the specific 5-bromouracil ((Br)U)-substituted sequence 5'-(G/C)[A]n = 1,2 (Br)U(Br)U-3' and proposed that a formed uracil-5-yl radical mainly abstracts the C1' hydrogen from the 5'-side of (Br)U(Br)U under 302-nm irradiation condition. In the present work, we performed photoirradiation of (Br)U-substituted DNA ...

Bacteriophage T5 induces a deoxyuridine B’-triphosphate nucleotidohydrolase (dUTPase) activity during infection of Escherichiu coli. A T5 mutant (T5 dut) unable to induce this dUTPase activity has been isolated. Although this mutant is viable, the E. coli dUTPase activity is not sufficiently active to exclude uracil from the progeny DNA and about 3% of the thymine is replaced by uracil. When th...

Various octadeoxynucleotides containing uracil at different positions were synthesized and submitted to the action of Escherichia coli and Micrococcus luteus uracil-DNA glycosylases. A uracil residue situated at the 5'-end was excised by the M.luteus enzyme but not by the E.coli one. Uracil residues located at the ultimate and penultimate positions at the 3'-end were not cleaved by either enzym...