Mechanistic insights into β-lactamase-catalysed carbapenem degradation through product characterisation
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...
| Main Authors: | , , , , , , , |
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| Format: | Journal article |
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Nature Research
2019
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| _version_ | 1797095506215698432 |
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| author | Lohans, C Freeman, E Van Groesen, E Tooke, C Hinchliffe, P Spencer, J Brem, J Schofield, C |
| author_facet | Lohans, C Freeman, E Van Groesen, E Tooke, C Hinchliffe, P Spencer, J Brem, J Schofield, C |
| author_sort | Lohans, C |
| collection | OXFORD |
| description | 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. |
| first_indexed | 2024-03-07T04:28:48Z |
| format | Journal article |
| id | oxford-uuid:cd986cf5-f433-4b32-b378-30edc5734827 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T04:28:48Z |
| publishDate | 2019 |
| publisher | Nature Research |
| record_format | dspace |
| spelling | oxford-uuid:cd986cf5-f433-4b32-b378-30edc57348272022-03-27T07:29:48ZMechanistic insights into β-lactamase-catalysed carbapenem degradation through product characterisationJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:cd986cf5-f433-4b32-b378-30edc5734827Symplectic Elements at OxfordNature Research2019Lohans, CFreeman, EVan Groesen, ETooke, CHinchliffe, PSpencer, JBrem, JSchofield, Cβ-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. |
| spellingShingle | Lohans, C Freeman, E Van Groesen, E Tooke, C Hinchliffe, P Spencer, J Brem, J Schofield, C Mechanistic insights into β-lactamase-catalysed carbapenem degradation through product characterisation |
| title | Mechanistic insights into β-lactamase-catalysed carbapenem degradation through product characterisation |
| title_full | Mechanistic insights into β-lactamase-catalysed carbapenem degradation through product characterisation |
| title_fullStr | Mechanistic insights into β-lactamase-catalysed carbapenem degradation through product characterisation |
| title_full_unstemmed | Mechanistic insights into β-lactamase-catalysed carbapenem degradation through product characterisation |
| title_short | Mechanistic insights into β-lactamase-catalysed carbapenem degradation through product characterisation |
| title_sort | mechanistic insights into β lactamase catalysed carbapenem degradation through product characterisation |
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