BACKGROUND Tegafur-uracil has become an important regimen in the treatment of metastatic colorectal cancer. Tegafur is a prodrug that is converted to 5-fluorouracil (5-FU) and has been reported to be less toxic and to have a higher therapeutic index. The additional advantage of tegafur is oral administration, an important consideration to improve the quality of life in these patients. Tegafur i...

A sensitive and selective method for determination of the uracil content in human DNA was first developed on the basis of high-performance liquid chromatography-tandem mass spectrometry. Uracil was excised from DNA using uracil DNA glycosylase. The released uracil was derivatized with 4-bromomethyl-7-methoxycoumarin, thereby forming bis-N,N'-(4-methylene-7-methoxycoumaryl)-uracil (uracil-MMC). ...

In the title compound, C(4)H(3)N(3)O(4)·H(2)O, mol-ecules of 5-nitro--uracil are hydrogen bonded in pairs across crystallographic centers of symmetry. The resulting dimers are also hydrogen bonded to the water mol-ecules, forming a three-dimensional network. The pyrimidine ring is almost planar (with a maximum deviation of 0.0156 (9) Å for the one of the N atoms) and the nitro group is rotated ...

Uracil-DNA glycosidase, an enzyme that catalyzes the release of free uracil from uracil-containing DNA, has been purified ll,OOO-fold from Escherichia coli cell extracts. The enzyme preparation was essentially homogenous, as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The native enzyme is a small monomeric protein of a molecular weight of 24,500 + 1,000. The enzyme e...

Uracil DNA N-glycosylase is a repair enzyme that releases uracil from DNA. A major function of this enzyme is presumably to protect the genome from pre-mutagenic uracil resulting from deamination of cytosine in DNA. Here, we report that human uracil DNA N-glycosylase also recognizes three uracil derivatives that are generated as major products of cytosine in DNA by hydroxyl radical attack or ot...

Recent investigations have shown that the animal microorganism, Tetrahymena geleii, requires an exogenous source of pyrimidine for growth (1). This requirement can be met by the addition of cytidylic acid or uracil to the medium (2). Cytosine and thymine are without activity. The failure to utilize the latter two free bases was interpreted as indicating a block in the ability of the organism to...

A uracil-DNA-glycosylase from Micrococcus luteus has been purified more than 3,000-fold. The enzyme preparation appears homogeneous, according to the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It is devoid of nonspecific endonucleases, specific endonucleases for apurinic and apyrimidinic sites, 3-methyladenine or 7-methylguanine-DNA-glycosylases. It behaves as a monom...

The role of the conserved histidine-187 located in the leucine intercalation loop of Escherichia coli uracil-DNA glycosylase (Ung) was investigated. Using site-directed mutagenesis, an Ung H187D mutant protein was created, overproduced, purified to apparent homogeneity, and characterized in comparison to wild-type Ung. The properties of Ung H187D differed from Ung with respect to specific activ...