Non-Nucleoside Inhibitors of BasE, an Adenylating Enzyme in the Siderophore Biosynthetic Pathway of the Opportunistic Pathogen Acinetobacter baumannii

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• 作者：Jo茫o Neres ; Curtis A. Engelhart ; Eric J. Drake ; Daniel J. Wilson ; Peng Fu ; Helena I. Boshoff ; Clifton E. Barry ; 3rd ; Andrew M. Gulick ; Courtney C. Aldrich
• 刊名：Journal of Medicinal Chemistry
• 出版年：2013
• 出版时间：March 28, 2013
• 年：2013
• 卷：56
• 期：6
• 页码：2385-2405
• 全文大小：824K
• 年卷期：v.56,no.6(March 28, 2013)
• ISSN：1520-4804

文摘

Siderophores are small-molecule iron chelators produced by bacteria and other microorganisms for survival under iron limiting conditions such as found in a mammalian host. Siderophore biosynthesis is essential for the virulence of many important Gram-negative pathogens including Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli. We performed high-throughput screening against BasE, which is involved in siderophore biosynthesis in A. baumannii, and identified 6-phenyl-1-(pyridin-4-ylmethyl)-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid 15. Herein we report the synthesis, biochemical, and microbiological evaluation of a systematic series of analogues of the HTS hit 15. Analogue 67 is the most potent analogue with a K_D of 2 nM against BasE. Structural characterization of the inhibitors with BasE reveals that they bind in a unique orientation in the active site, occupying all three substrate binding sites, and thus can be considered as multisubstrate inhibitors. These results provide a foundation for future studies aimed at increasing both enzyme potency and antibacterial activity.