Clinical inhibitor-resistant mutants of the β-lactamase TEM-1 at amino-acid position 69

Chaibi, El Bachir; Péduzzi, J.; Farzaneh, S.; Barthélémy, Michel; Sirot, D.; Labia, Roger

doi:10.1016/s0167-4838(97)00127-1

Cited by 36 publications

(44 citation statements)

References 38 publications

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“…Amino acid substitutions in TEM and SHV result in resistance to clavulanate by two primary mechanisms: (i) alterations in the geometry of shape of the oxyanion hole and (ii) changes in the position of Ser130 or Arg244 (33,73,101,120,408,411,416). The individual residues that are most commonly substituted in IR TEM enzymes are Arg244, the nearby Asn276 and Arg275, Met69, and the active-site Ser130 (www .lahey.org/studies/webt.asp) (Fig.…”

Section: Substitutions In Class a Enzymes Conferring Inhibitor Resistmentioning

confidence: 99%

“…The TEM variants, Met69Ile, -Val, and -Leu, each show an approximately 10-fold increase in K I and 10-fold decrease in k inact , leading to a 100-fold decrease in inhibitory efficiency (k inact /K I ) (73). Evidence from X-ray crystallography and molecular dynamic studies has revealed that each substitution introduces subtle active-site changes that perturb inhibitor recognition and enzyme catalysis (262,438).…”

Section: Substitutions In Class a Enzymes Conferring Inhibitor Resistmentioning

confidence: 99%

“…It is axiomatic that in order for an inhibitor to work efficiently, it must exhibit high affinity for its target. This principle is emphasized by the development of clavulanate resistance in TEM-1 and SHV-1 ␤-lactamases mediated by substitution of amino acid residues 69, 130, 244, and 276, leading to increased inhibitor K I s and/or IC 50 s (73,153,378,411). Particularly promising are those inhibitors that maintain high affinities across different groups of ␤-lactamases, such as the C-2-substituted sulfone LN-1-255, the methylidene penems, and phosphonates which achieve nM inhibition of class A, C, and D (4, 25, 63, 245, 322, 441) (Drawz et al, unpublished data).…”

Section: Lessons Learnedmentioning

confidence: 99%

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Three Decades of β-Lactamase Inhibitors

Drawz¹,

2010

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SUMMARYSince the introduction of penicillin, β-lactam antibiotics have been the antimicrobial agents of choice. Unfortunately, the efficacy of these life-saving antibiotics is significantly threatened by bacterial β-lactamases. β-Lactamases are now responsible for resistance to penicillins, extended-spectrum cephalosporins, monobactams, and carbapenems. In order to overcome β-lactamase-mediated resistance, β-lactamase inhibitors (clavulanate, sulbactam, and tazobactam) were introduced into clinical practice. These inhibitors greatly enhance the efficacy of their partner β-lactams (amoxicillin, ampicillin, piperacillin, and ticarcillin) in the treatment of seriousEnterobacteriaceaeand penicillin-resistant staphylococcal infections. However, selective pressure from excess antibiotic use accelerated the emergence of resistance to β-lactam-β-lactamase inhibitor combinations. Furthermore, the prevalence of clinically relevant β-lactamases from other classes that are resistant to inhibition is rapidly increasing. There is an urgent need for effective inhibitors that can restore the activity of β-lactams. Here, we review the catalytic mechanisms of each β-lactamase class. We then discuss approaches for circumventing β-lactamase-mediated resistance, including properties and characteristics of mechanism-based inactivators. We next highlight the mechanisms of action and salient clinical and microbiological features of β-lactamase inhibitors. We also emphasize their therapeutic applications. We close by focusing on novel compounds and the chemical features of these agents that may contribute to a “second generation” of inhibitors. The goal for the next 3 decades will be to design inhibitors that will be effective for more than a single class of β-lactamases.

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Section: Substitutions In Class a Enzymes Conferring Inhibitor Resistmentioning

confidence: 99%

Section: Substitutions In Class a Enzymes Conferring Inhibitor Resistmentioning

confidence: 99%

Section: Lessons Learnedmentioning

confidence: 99%

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Three Decades of β-Lactamase Inhibitors

Drawz¹,

2010

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“…Two of them, Met69Leu and Asn276Asp, have already been described in other IRTs produced by clinical strains, either alone for Met69Leu in the TEM-33 enzyme (44) and Asn276Asp in the TEM-84 enzyme (24) or in combination in the TEM-35 ␤-lactamase (7,44). In vitro amino acid replacements at these two positions have been recognized as major contributors to clinically significant levels of resistance to ␤-lactamase inactivators (10,11,21,37,42).…”

Section: Discussionmentioning

confidence: 99%

TEM-80, a Novel Inhibitor-Resistant β-Lactamase in a Clinical Isolate of Enterobacter cloacae

Arpin

Labia

Dubois

et al. 2002

Antimicrob Agents Chemother

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Enterobacter cloacae Ecl261 was isolated with Escherichia coli Ec257 from the urine of a patient living in a nursing home. Both isolates were resistant to ticarcillin (MICs, 1,024 g/ml), without significant potentiation of its activity by 2 g of clavulanate per ml (MICs, 512 g/ml), and susceptible to naturally active cephalosporins. This inhibitor-resistant phenotype was conferred in both strains by similar conjugative plasmids of 40 kb (Ecl261) and 30 kb (Ec257), which also conveyed resistance to sulfonamides and trimethoprim. Clinical and transconjugant strains produced a ␤-lactamase with a pI of 5.2 which belonged to the TEM family, as indicated by specific PCR amplification. Compared with TEM-1, this enzyme exhibited lower catalytic efficiencies (14-and 120-fold less for amoxicillin and ticarcillin, respectively), and higher concentrations of ␤-lactamase inhibitors were required to yield a 50% reduction in benzylpenicillin hydrolysis (750-, 82-, and 50-fold higher concentrations for clavulanate, sulbactam, and tazobactam, respectively). Gene sequencing revealed four nucleotide differences with the nucleotide sequence of bla TEM-1A . The first replacement (T32C), located in the promoter region, was described as being responsible for the increase in the level of ␤-lactamase production. The three other changes led to amino acid substitutions that define a new inhibitor-resistant TEM (IRT) ␤-lactamase, TEM-80 (alternate name, IRT-24). Two of them, Met69Leu and Asn276Asp, have previously been related to inhibitor resistance. The additional mutation, Ile127Val, was demonstrated by site-directed mutagenesis to have a very weak effect, at least alone, on the IRT phenotype. This is the first description of an IRT ␤-lactamase in E. cloacae. The horizontal transfer of bla TEM-80 may have occurred either from Ec257 to Ecl261 or in the reverse order.

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“…An alternative hypothesis is that the increasing hydrophobicity of the 69 residue narrows the active site such that betalactamase inhibitors are more readily hydrolyzed (49). Studying clinical inhibitor-resistant mutants of TEM-1 at amino acid Met69 of TEM-1, altering the Met69 to Leu, Ile and Val, Chaibi et al (50) have advanced the hypothesis that the methyl group of Ile69 and Val69 produce steric constraints with the side chain of Asn 170 as well as the main chain nitrogen of Ser70. Leu at the 69 position also exerts a hydrophobic effect.…”

Section: Amino Acid Substitutions Conferring Resistance To Beta−lactamentioning

confidence: 99%

Inhibitor resistant class A beta-lactamases

Rice

1999

Front Biosci

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Clinical inhibitor-resistant mutants of the β-lactamase TEM-1 at amino-acid position 69

Cited by 36 publications

References 38 publications

Three Decades of β-Lactamase Inhibitors

Three Decades of β-Lactamase Inhibitors

TEM-80, a Novel Inhibitor-Resistant β-Lactamase in a Clinical Isolate of Enterobacter cloacae

Inhibitor resistant class A beta-lactamases

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