title: Synthesis and evaluation of a mechanism-based inhibitor of KDO8P synthase.
abstract: The enzyme 3-deoxy-D-manno-2-octulosonate-8-phosphate (KDO8P) synthase catalyzes the condensation reaction between phosphoenolpyruvate (PEP) and D-arabinose 5-phosphate (A5P) to produce KDO8P and inorganic phosphate. In attempts to investigate the lack of antibacterial activity of the most potent inhibitor of KDO8P synthase, the amino phosphonophosphate 3, we have synthesized its hydrolytically stable isosteric phosphonate analogue 4 and tested it as an inhibitor of the enzyme. The synthesis of 4 was accomplished in a one step procedure by employing the direct reductive amination in aqueous media between unprotected sugar phosphonate and glyphosate. The analogue 4 proved to be a competitive inhibitor of KDO8P synthase with respect to both substrates A5P and PEP binding. In vitro antibacterial tests against a series of different Gram-negative organisms establish that both inhibitors (3 and 4) lack antibacterial activity probably due to their reduced ability to penetrate the bacterial cell membrane.
authors.affiliation: Department of Chemistry, Technion--Israel Institute of Technology, 32000, Haifa, Israel.
authors.forename: Valery
authors.initials: V
authors.lastname: Belakhov
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Dovgolevsky
authors.forename: Emilia
authors.initials: E
authors.lastname: Rabkin
authors.forename: Smadar
authors.initials: S
authors.lastname: Shulami
authors.forename: Yuval
authors.initials: Y
authors.lastname: Shoham
authors.forename: Timor
authors.initials: T
authors.lastname: Baasov
mesh_terms: D000446:Aldehyde-Lyases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects; D008958:Models, Molecular; D015394:Molecular Structure; D013053:Spectrophotometry
chemical_list: D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; C020011:2-dehydro-3-deoxyphosphooctonate aldolase; D000446:Aldehyde-Lyases