Uridine-based inhibitors as new leads for antibiotics targeting Escherichia coli LpxC.

Published

Journal Article

The UDP-3-O-(R-3-hydroxyacyl)-N-acetylglucosamine deacetylase LpxC catalyzes the committed reaction of lipid A (endotoxin) biosynthesis in Gram-negative bacteria and is a validated antibiotic target. Although several previously described compounds bind to the unique acyl chain binding passage of LpxC with high affinity, strategies to target the enzyme's UDP-binding site have not been reported. Here the identification of a series of uridine-based LpxC inhibitors is presented. The most potent examined, 1-68A, is a pH-dependent, two-step, covalent inhibitor of Escherichia coli LpxC that competes with UDP to bind the enzyme in the first step of inhibition. Compound 1-68A exhibits a K(I) of 54 muM and a maximal rate of inactivation (k(inact)) of 1.7 min(-1) at pH 7.4. Dithiothreitol, glutathione and the C207A mutant of E. coli LpxC prevent the formation of a covalent complex by 1-68A, suggesting a role for Cys-207 in inhibition. The inhibitory activity of 1-68A and a panel of synthetic analogues identified moieties necessary for inhibition. 1-68A and a 2-dehydroxy analogue, 1-68Aa, inhibit several purified LpxC orthologues. These compounds may provide new scaffolds for extension of existing LpxC-inhibiting antibiotics to target the UDP binding pocket.

Full Text

Duke Authors

Cited Authors

  • Barb, AW; Leavy, TM; Robins, LI; Guan, Z; Six, DA; Zhou, P; Hangauer, MJ; Bertozzi, CR; Raetz, CRH

Published Date

  • April 14, 2009

Published In

Volume / Issue

  • 48 / 14

Start / End Page

  • 3068 - 3077

PubMed ID

  • 19256534

Pubmed Central ID

  • 19256534

Electronic International Standard Serial Number (EISSN)

  • 1520-4995

Digital Object Identifier (DOI)

  • 10.1021/bi900167q

Language

  • eng

Conference Location

  • United States