Skip to content

Mechanistic Insights into β-Lactamase-Catalysed Carbapenem Degradation Through Product Characterisation

Research output: Contribution to journalArticle

Original languageEnglish
Article number13608
Number of pages9
JournalScientific Reports
Volume9
DOIs
DateAccepted/In press - 15 Aug 2019
DatePublished (current) - 20 Sep 2019

Abstract

β-Lactamases are a major threat to the clinical use of carbapenems, which are often antibiotics of last resort. Despite this, the reaction outcomes and mechanisms by which β-lactamases degrade carbapenems are still not fully understood. The carbapenem bicyclic core consists of a β-lactam ring fused to a pyrroline ring. Following β-lactamase-mediated opening of the β-lactam, the pyrroline may interconvert between an enamine (2-pyrroline) form and two epimeric imine (1-pyrroline) forms; previous crystallographic and spectroscopic studies have reported all three of these forms in the contexts of hydrolysis by different β-lactamases. As we show by NMR spectroscopy, the serine β-lactamases (KPC-2, SFC-1, CMY-10, OXA-23, and OXA-48) and metallo-β-lactamases (NDM-1, VIM-1, BcII, CphA, and L1) tested all degrade carbapenems to preferentially give the Δ2 (enamine) and/or (R)-Δ1 (imine) products. Rapid non-enzymatic tautomerisation of the Δ2 product to the (R)-Δ1 product prevents assignment of the nascent enzymatic product by NMR. The observed stereoselectivity implies that carbapenemases control the form of their pyrroline ring intermediate(s)/product(s), thereby preventing pyrroline tautomerisation from inhibiting catalysis.

    Research areas

  • Antibiotics, Antimicrobial resistance, Enzyme mechanisms, hydrolases

Download statistics

No data available

Documents

Documents

  • Full-text PDF (final published version)

    Rights statement: This is the final published version of the article (version of record). It first appeared online via Springer Nature at https://doi.org/10.1038/s41598-019-49264-0 . Please refer to any applicable terms of use of the publisher.

    Final published version, 2.62 MB, PDF document

    Licence: CC BY

DOI

View research connections

Related faculties, schools or groups