title: Synthesis of N4-substituted CTP by mammalian CTP synthetase.
abstract: Highly purified CTP synthetase from Ehrlich ascites tumor cells catalyzes the formation of N4-substituted CTP from UTP and hydroxylamine and its derivatives. The products with hydroxylamine and O-methylhydroxylamine were identified as N4-hydroxyCTP and N4-methoxyCTP by absorption spectra and chromatographic behavior on Dowex column, respectively. The weak nucleophilic amines such as methylamine, ethylamine or diethylamine and a less nucleophilic amine, sulfamic acid, did not react with UTP. These results suggest that the nucleophilicity and basicity of amines are important in the enzymic reaction with UTP.
mesh_terms: D000818:Animals; D019731:Carbon-Nitrogen Ligases; D002286:Carcinoma, Ehrlich Tumor / Q000201:enzymology*; D002852:Chromatography, Ion Exchange / Q000379:methods; D003570:Cytidine Triphosphate / Q000031:analogs & derivatives* / Q000302:isolation & purification; D003597:Cytosine Nucleotides; D007700:Kinetics; D008025:Ligases / Q000378:metabolism*; D051379:Mice
chemical_list: D003597:Cytosine Nucleotides; D003570:Cytidine Triphosphate; D008025:Ligases; D019731:Carbon-Nitrogen Ligases; C019951:CTP synthetase