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). ...

Difluorocarbene, generated from trimethylsilyl fluorosulfonyldifluoroacetate (TFDA), reacts with the uridine and adenosine substrates preferentially at the enolizable amide moiety of the uracil ring and the 6-amino group of the purine ring. 2',3'-Di-O-acetyl-3'-deoxy-3'-methyleneuridine reacts with TFDA to produce 4-O-difluoromethyl product derived from an insertion of difluorocarbene into the ...

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...

The tumor-promoting effect of uracil-induced calculi on rat urinary bladder carcinogenesis was investigated in male F344 rats pretreated with /V-butyl-A/-(4-hydroxybutyl)nitrosamine (BBN). Since uracil-in duced calculi and papillomatosis of the bladder are reversible, uracil was given for a limited period after the treatment with BBN. Animals were given 0.05% BBN in their drinking water for 4 w...

Uracil-DNA glycosylases (UDGs) of the uracil-N-glycosylase (UNG) family are the primary DNA repair enzymes responsible for removal of inappropriate uracil from DNA. Recent studies further suggest that the nuclear human UNG2 and the UDGs of large DNA viruses may coordinate with their DNA polymerase accessory factors to enhance DNA replication. Based on its amino acid sequence, the putative UDG o...

Laboratory experiments have shown that the UV photo-irradiation of low-temperature ices of astrophysical interest leads to the formation of organic molecules, including molecules important for biology such as amino acids, quinones, and amphiphiles. When pyrimidine is introduced into these ices, the products of irradiation include the nucleobases uracil, cytosine, and thymine, the informational ...