Kinetic interactions of tazobactam with beta-lactamases from all major structural classes

Bush, Karen; Macalintal, C.; Rasmussen, Beth A.; Lee, V. J.; Yang, Youjun

doi:10.1128/aac.37.4.851

Cited by 250 publications

(193 citation statements)

References 31 publications

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“…In contrast, TEM-1 with clavulanic acid displayed a partial return of activity, which is attributed to rearrangement from the acylated enzyme form to additional irreversible acyl-enzyme species (13). TEM-1 inhibition by tazobactam follows a branched deacylation pathway that favors hydrolysis over rearrangement (14), which in the offrate assay, manifested as a rapid return to nearly full activity.…”

Section: Resultsmentioning

confidence: 96%

Avibactam is a covalent, reversible, non–β-lactam β-lactamase inhibitor

Ehmann

Jahić

Ross

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

438

436

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Avibactam is a β-lactamase inhibitor that is in clinical development, combined with β-lactam partners, for the treatment of bacterial infections comprising Gram-negative organisms. Avibactam is a structural class of inhibitor that does not contain a β-lactam core but maintains the capacity to covalently acylate its β-lactamase targets. Using the TEM-1 enzyme, we characterized avibactam inhibition by measuring the on-rate for acylation and the offrate for deacylation. The deacylation off-rate was 0.045 min −1 , which allowed investigation of the deacylation route from TEM-1. Using NMR and MS, we showed that deacylation proceeds through regeneration of intact avibactam and not hydrolysis. Other than TEM-1, four additional clinically relevant β-lactamases were shown to release intact avibactam after being acylated. We showed that avibactam is a covalent, slowly reversible inhibitor, which is a unique mechanism of inhibition among β-lactamase inhibitors.antibacterial | drug discovery | enzymology T here is an urgent need for new antibacterial agents that are active against drug-resistant bacteria. In particular, some Gram-negative pathogens have accumulated enough resistance mechanisms to render them virtually untreatable by modern antibacterial chemotherapy (1, 2). A mainstay for treatment of Gram-negative infections is the β-lactam classes of drugs. The most common form of resistance to β-lactam antibiotics is the expression of various β-lactamase enzymes capable of hydrolyzing the β-lactam ring of β-lactam drugs, rendering them ineffective. As new β-lactams have been introduced into clinical use, a changing landscape of β-lactamases has been selected and disseminated. Presently, over 1,000 β-lactamases have been documented comprising several structural classes and a wide range of substrate promiscuities and catalytic efficiencies (3, 4).In efforts to restore the efficacy of β-lactam antibiotics, β-lactamases have also been targeted with a variety of inhibitors (5, 6). The three inhibitors approved for clinical use are clavulanic acid, tazobactam, and sulbactam, all of which contain a β-lactam core. A challenge for the development of broad-spectrum β-lactamase inhibitors is the mechanistic diversity in β-lactamase enzymes, with the largest distinction being between the enzyme classes that use a serine residue as the nucleophilic species and the metallo-β-lactamases, which directly activate water for hydrolysis (7). A shared mechanistic feature of the marketed β-lactam-based inhibitors is their reaction with the serine enzymes to form a covalent acylenzyme intermediate. On ring opening, the acyl-enzyme intermediate can undergo additional rearrangements or be released through hydrolysis to regenerate the active β-lactamase enzyme (8). Originally designed to combat class A serine β-lactamase enzymes such as TEM-1, the clinical use of β-lactam-based inhibitors has been diminished by the emergence of enzymes against which they are ineffective. Despite intense investigation by pharmaceutical companies, no new β-lactamas...

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Section: Resultsmentioning

confidence: 96%

Avibactam is a covalent, reversible, non–β-lactam β-lactamase inhibitor

Ehmann

Jahić

Ross

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

438

436

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“…This species forms on a millisecond time scale, however, we were unable to directly detect its formation due to the low extinction coefficient associated with opening of the ␤-lactam ring (23). The smaller chromophore was masked by the trailing end of the much larger one of the ␣,␤-unsaturated systems of species 4 and 5, which form on the same time scale.…”

Section: Susceptibility Of Ges-2 To Tazobactam-we Had Previouslymentioning

confidence: 87%

“…Prior studies with SHV-1 were unable to distinguish the two isomers, thus they were only able to monitor formation of the total enamine species (23,48). The two isomers in complex with GES-2 show a difference in max of 20 nm, allowing us to monitor each species separately ( Fig.…”

Section: Discussionmentioning

confidence: 99%

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Identification of Products of Inhibition of GES-2 β-Lactamase by Tazobactam by X-ray Crystallography and Spectrometry

Frase

Smith

Tóth

et al. 2011

Journal of Biological Chemistry

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The GES-2 ␤-lactamase is a class A carbapenemase, the emergence of which in clinically important bacterial pathogens is a disconcerting development as the enzyme confers resistance to carbapenem antibiotics. Tazobactam is a clinically used inhibitor of class A ␤-lactamases, which inhibits the GES-2 enzyme effectively, restoring susceptibility to ␤-lactam antibiotics. We have investigated the details of the mechanism of inhibition of the GES-2 enzyme by tazobactam. By the use of UV spectrometry, mass spectroscopy, and x-ray crystallography, we have documented and identified the involvement of a total of seven distinct GES-2⅐tazobactam complexes and one product of the hydrolysis of tazobactam that contribute to the inhibition profile. The x-ray structures for the GES-2 enzyme are for both the native (1.45 Å ) and the inhibited complex with tazobactam (1.65 Å ). This is the first such structure of a carbapenemase in complex with a clinically important ␤-lactam inhibitor, shedding light on the structural implications for the inhibition process.

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“…28−31 In vitro, the inhibitory activities of all compounds prepared were tested against the MβLs on an Agilent UV8453 spectrometer as described by Bush et al, using cefazolin (imipenem for ImiS) as the substrate. 32 The substrate concentrations were varied between 26 and 160 μM, and inhibitor concentrations were varied between 15 nM and 10 μM. Enzyme and inhibitor were preincubated for 60 min before starting the kinetic experiments.…”

mentioning

confidence: 99%

Triazolylthioacetamide: A Valid Scaffold for the Development of New Delhi Metallo-β-Lactmase-1 (NDM-1) Inhibitors

Zhai

Zhang

Kang

et al. 2016

ACS Med. Chem. Lett.

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ABSTRACT:The metallo-β-lactamases (MβLs) cleave the β-lactam ring of β-lactam antibiotics, conferring resistance against these drugs to bacteria. Twenty-four triazolylthioacetamides were prepared and evaluated as inhibitors of representatives of the three subclasses of MβLs. All these compounds exhibited specific inhibitory activity against NDM-1 with an IC 50 value range of 0.15−1.90 μM, but no activity against CcrA, ImiS, and L1 at inhibitor concentrations of up to 10 μM. Compounds 4d and 6c are partially mixed inhibitors with K i values of 0.49 and 0.63 μM using cefazolin as the substrate. Structure−activity relationship studies reveal that replacement of hydrogen on the aromatic ring by chlorine, heteroatoms, or alkyl groups can affect bioactivity, while leaving the aromatic ring of the triazolylthiols unmodified maintains the inhibitory potency. Docking studies reveal that the typical potent inhibitors of NDM-1, 4d and 6c, form stable interactions in the active site of NDM-1, with the triazole bridging Zn1 and Zn2, and the amide interacting with Lys 211 (Lys224).

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Kinetic interactions of tazobactam with beta-lactamases from all major structural classes

Cited by 250 publications

References 31 publications

Avibactam is a covalent, reversible, non–β-lactam β-lactamase inhibitor

Avibactam is a covalent, reversible, non–β-lactam β-lactamase inhibitor

Identification of Products of Inhibition of GES-2 β-Lactamase by Tazobactam by X-ray Crystallography and Spectrometry

Triazolylthioacetamide: A Valid Scaffold for the Development of New Delhi Metallo-β-Lactmase-1 (NDM-1) Inhibitors

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