Synthesis of a Novel Boronic Acid Transition State Inhibitor, MB076: A Heterocyclic Triazole Effectively Inhibits Acinetobacter -Derived Cephalosporinase Variants with an Expanded-Substrate Spectrum.
Rachel A PowersCynthia M JuneMicah C FernandoErin R FishOlivia L MaurerRachelle M BaumannTrevor J BeardsleyMagdalena A TaracilaSusan D RudinKristine M HujerAndrea M HujerNicolo SantiValentina VillamilMaria Luisa IntrovigneFabio PratiEmilia CaselliRobert A BonomoBradley J WallarPublished in: Journal of medicinal chemistry (2023)
Class C Acinetobacter -derived cephalosporinases (ADCs) represent an important target for inhibition in the multidrug-resistant pathogen Acinetobacter baumannii . Many ADC variants have emerged, and characterization of their structural and functional differences is essential. Equally as important is the development of compounds that inhibit all prevalent ADCs despite these differences. The boronic acid transition state inhibitor, MB076 , a novel heterocyclic triazole with improved plasma stability, was synthesized and inhibits seven different ADC β-lactamase variants with K i values <1 μM. MB076 acted synergistically in combination with multiple cephalosporins to restore susceptibility. ADC variants containing an alanine duplication in the Ω-loop, specifically ADC-33, exhibited increased activity for larger cephalosporins, such as ceftazidime, cefiderocol, and ceftolozane. X-ray crystal structures of ADC variants in this study provide a structural context for substrate profile differences and show that the inhibitor adopts a similar conformation in all ADC variants, despite small changes near their active sites.
Keyphrases
- acinetobacter baumannii
- multidrug resistant
- copy number
- gram negative
- diffusion weighted imaging
- diffusion weighted
- drug resistant
- pseudomonas aeruginosa
- escherichia coli
- contrast enhanced
- klebsiella pneumoniae
- magnetic resonance imaging
- computed tomography
- dna methylation
- high resolution
- molecular dynamics simulations
- mass spectrometry
- genome wide