title: Mode of action of oxanosine, a novel nucleoside antibiotic.
abstract: Oxanosine, a novel nucleoside, inhibits the growth of Escherichia coli K-12 on peptone agar, but not on Nutrient agar. This antibiotic activity was found to be bacteriostatic and was antagonized by guanine, guanosine, and guanylic acid. The growth of leukemia L 1210 cell was also inhibited by oxanosine, and the inhibition was reversed by guanylic acid. Oxanosine was confirmed to be a competitive inhibitor of GMP synthetase (E.C. 6.3.5.2) and the Ki value was 7.4 X 10(-4) M.
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D019731:Carbon-Nitrogen Ligases; D004926:Escherichia coli / Q000187:drug effects; D006151:Guanosine / Q000494:pharmacology; D006157:Guanosine Monophosphate / Q000494:pharmacology; D007939:Leukemia L1210 / Q000188:drug therapy; D008025:Ligases / Q000037:antagonists & inhibitors; D012263:Ribonucleosides / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D012263:Ribonucleosides; D006151:Guanosine; C032886:oxanosine; D006157:Guanosine Monophosphate; D008025:Ligases; D019731:Carbon-Nitrogen Ligases; C020828:GMP synthase (glutamine-hydrolyzing)