932-52-5Relevant articles and documents
Discovery of a bacterial 5-methylcytosine deaminase
Hitchcock, Daniel S.,Fedorov, Alexander A.,Fedorov, Elena V.,Almo, Steven C.,Raushel, Frank M.
, p. 7426 - 7435 (2015/04/16)
5-Methylcytosine is found in all domains of life, but the bacterial cytosine deaminase from Escherichia coli (CodA) will not accept 5-methylcytosine as a substrate. Since significant amounts of 5-methylcytosine are produced in both prokaryotes and eukaryotes, this compound must eventually be catabolized and the fragments recycled by enzymes that have yet to be identified. We therefore initiated a comprehensive phylogenetic screen for enzymes that may be capable of deaminating 5-methylcytosine to thymine. From a systematic analysis of sequence homologues of CodA from thousands of bacterial species, we identified putative cytosine deaminases where a "discriminating" residue in the active site, corresponding to Asp-314 in CodA from E. coli, was no longer conserved. Representative examples from Klebsiella pneumoniae (locus tag: Kpn00632), Rhodobacter sphaeroides (locus tag: Rsp0341), and Corynebacterium glutamicum (locus tag: NCgl0075) were demonstrated to efficiently deaminate 5-methylcytosine to thymine with values of kcat/Km of 1.4 × 105, 2.9 × 104, and 1.1 × 103 M-1 s-1, respectively. These three enzymes also catalyze the deamination of 5-fluorocytosine to 5-fluorouracil with values of kcat/Km of 1.2 × 105, 6.8 × 104, and 2.0 × 102 M-1 s-1, respectively. The three-dimensional structure of Kpn00632 was determined by X-ray diffraction methods with 5-methylcytosine (PDB id: 4R85), 5-fluorocytosine (PDB id: 4R88), and phosphonocytosine (PDB id: 4R7W) bound in the active site. When thymine auxotrophs of E. coli express these enzymes, they are capable of growth in media lacking thymine when supplemented with 5-methylcytosine. Expression of these enzymes in E. coli is toxic in the presence of 5-fluorocytosine, due to the efficient transformation to 5-fluorouracil.
5-(Acridin-9-ylamino)uracil-A hydrolytically labile nucleobase modification in peptide nucleic acid
Matarazzo, Augusto,Moustafa, Mohamed E.,Hudson, Robert H.E.
supporting information, p. 1202 - 1206 (2014/01/06)
5-Aminouracil (5-AU) is a readily available yet underutilized starting material for the synthesis of labelled nucleobase analogues. We have prepared the derivative of 5-AU with the amine-reactive chromophore 9-chloroacridine for the purpose of investigating its potential as a base-discriminating fluorophore. 9-Chloroacridine readily undergoes substitution by reaction with 5-AU to yield a fluorescent nucleobase that after standard manipulations produced a monomer suitable for incorporation into peptide nucleic acid (PNA) by fluorenylmethyloxycarbonyl (Fmoc)-based oligomerization chemistry. Although the monomer was stable in organic solvents, once incorporated into an oligomer the 5-substitution was found to be thermally labile and hydrolyzed to a small degree in neutral aqueous solution during study of its hybridization to cDNA. We have determined that 5-(acridin-9-ylamino)uracil and related derivatives produce the highly fluorescent acridone and 5-AU by hydrolysis in water.
PYRIDO[3,2-d]PYRIMIDINE PI3K DELTA INHIBITOR COMPOUNDS AND METHODS OF USE
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Page/Page column 58, (2011/09/16)
Formula I compounds, including stereoisomers, geometric isomers, tautomers, metabolites and pharmaceutically acceptable salts thereof, are useful for inhibiting the delta isoform of PI3K, and for treating disorders mediated by lipid kinases such as inflammation, immunological disorders, and cancer. Methods of using compounds of Formula I for in vitro, in situ, and in vivo diagnosis, prevention or treatment of such disorders in mammalian cells, or associated pathological conditions, are disclosed.
PROCESS FOR STRAIGHTENING KERATIN FIBRES WITH A HEATING MEANS AND DENATURING AGENTS
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, (2010/03/02)
The invention relates to a process for straightening keratin fibres, comprising: (i) a step in which a straightening composition containing at least two denaturing agents is applied to the keratin fibres, (ii) a step in which the temperature of the keratin fibres is raised, using a heating means, to a temperature of between 110 and 250° C.
Composition of matter having bioactive properties
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, (2008/06/13)
Particles of coordinated complex comprising a basic, hydrous polymer and a capacitance adding compound, as well as methods for their production, are described. These complexes exhibit a high degree of bioactivity making them suitable for a broad range of applications through their incorporation into conventional vehicles benefiting from antimicrobial and similar properties.
