Design, Synthesis, and Evaluation of a Potent Mechanism-Based Inhibitor for the TEM .beta.-Lactamase with Implications for the Enzyme Mechanism

Miyashita, Kazuyuki; Massova, Irina; Taibi, Pascale; Mobashery, Shahriar

doi:10.1021/ja00150a003

Cited by 52 publications

(55 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The position of this water molecule is crystallographically conserved (31,36,41) unlike in class D enzymes (42)(43)(44). Perturbation of the hydrogen bonding network of this water molecule or the physical displacements of the water molecule by the steric bulk of the C-6 side chains of a ␤-lactam are possible mechanisms to render the ␤-lactamase deacylation-deficient (20,(45)(46)(47). This is the goal in designing new generations of ␤-lactams that are stable toward ␤-lactamases (47).…”

Section: Mechanism Of ␤-Lactammentioning

confidence: 99%

“…Our study addresses the carbamylation state of its conserved lysine residue, and the role of the lysine-carbamate functional group in OXA-58 catalysis. In addition, we have probed the catalytic mechanism of OXA-58 with a series of 6␣-and 6␤-hydroxyalkyl penicillin derivatives (20,21). Our study provides insights into the mechanism of inhibition of these enzymes by 6␣-hydroxyalkyl penicillanate, and the mechanism of carbapenem hydrolysis by CHDLs.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Hydrolytic Mechanism of OXA-58 Enzyme, a Carbapenem-hydrolyzing Class D β-Lactamase from Acinetobacter baumannii

Verma

Testero

Amini

et al. 2011

Journal of Biological Chemistry

View full text Add to dashboard Cite

Background: OXA-58 is a carbapenem-hydrolyzing class D ␤-lactamase (CHDL) found in Acinetobacter baumannii. Results: OXA-58 exploits a carbamylated lysine in its catalysis. The deacylating water molecule comes from the ␣-face. Conclusion: CHDLs employ the same hydrolytic machinery as oxacillinases. Structural changes in the active site may lead to imipenem hydrolysis. Significance: This study provides insights for the design of CHDL inactivators.

show abstract

Section: Mechanism Of ␤-Lactammentioning

confidence: 99%

mentioning

confidence: 99%

Hydrolytic Mechanism of OXA-58 Enzyme, a Carbapenem-hydrolyzing Class D β-Lactamase from Acinetobacter baumannii

Verma

Testero

Amini

et al. 2011

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…) which produce the highest residual MICs of ampicillin also confer the highest MICs of ceftazidime (16,32, and 8 g/ml, respectively).…”

mentioning

confidence: 95%

Effects on Substrate Profile by Mutational Substitutions at Positions 164 and 179 of the Class A TEMpUC19 β-Lactamase from Escherichia coli

Vakulenko¹,

Taibi-Tronche²,

Tóth³

et al. 1999

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

We investigated the effects of mutations at positions 164 and 179 of the TEM pUC19 ␤-lactamase on turnover of substrates. The direct consequence of some mutations at these sites is that clinically important expanded-spectrum ␤-lactams, such as third-generation cephalosporins, which are normally exceedingly poor substrates for class A ␤-lactamases, bind the active site of these mutant enzymes more favorably. We employed site-saturation mutagenesis at both positions 164 and 179 to identify mutant variants of the parental enzyme that conferred resistance to expanded-spectrum ␤-lactams by their enhanced ability to turn over these antibiotic substrates. Four of these mutant variants, Arg 164 3 Asn, Arg 164 3 Ser, Asp 179 3 Asn, and Asp 179 3 Gly, were purified and the details of their catalytic properties were examined in a series of biochemical and kinetic experiments. The effects on the kinetic parameters were such that either activity with the expanded-spectrum ␤-lactams remained unchanged or, in some cases, the activity was enhanced. The affinity of the enzyme for these poorer substrates (as defined by the dissociation constant, K s ) invariably increased. Computation of the microscopic rate constants (k 2 and k 3 ) for turnover of these poorer substrates indicated either that the rate-limiting step in turnover was the deacylation step (governed by k 3 ) or that neither the acylation nor deacylation became the sole rate-limiting step. In a few instances, the rate constants for both the acylation (k 2 ) and deacylation (k 3 ) of the extended-spectrum ␤-lactamase were enhanced. These results were investigated further by molecular modeling experiments, using the crystal structure of the TEM pUC19 ␤-lactamase. Our results indicated that severe steric interactions between the large 7␤ functionalities of the expanded-spectrum ␤-lactams and the ⍀-loop secondary structural element near the active site were at the root of the low affinity by the enzyme for these substrates. These conclusions were consistent with the proposal that the aforementioned mutations would enlarge the active site, and hence improve affinity.

show abstract

“…There are compounds in development which inhibit class C enzymes (chromosomal beta−lactamases) (57). Further clinical testing is awaited with great anticipation.…”

Section: Treatment Options Future Prospects and Evolutionary Concernsmentioning

confidence: 99%

Inhibitor resistant class A beta-lactamases

Rice

1999

Front Biosci

View full text Add to dashboard Cite

Design, Synthesis, and Evaluation of a Potent Mechanism-Based Inhibitor for the TEM .beta.-Lactamase with Implications for the Enzyme Mechanism

Cited by 52 publications

References 0 publications

Hydrolytic Mechanism of OXA-58 Enzyme, a Carbapenem-hydrolyzing Class D β-Lactamase from Acinetobacter baumannii

Hydrolytic Mechanism of OXA-58 Enzyme, a Carbapenem-hydrolyzing Class D β-Lactamase from Acinetobacter baumannii

Effects on Substrate Profile by Mutational Substitutions at Positions 164 and 179 of the Class A TEMpUC19 β-Lactamase from Escherichia coli

Inhibitor resistant class A beta-lactamases

Contact Info

Product

Resources

About