Differential Binding of Co(II) and Zn(II) to Metallo-β-Lactamase Bla2 from <i>Bacillus anthracis</i>

Hawk, Megan J.; Breece, Robert M.; Hajdin, Christine E.; Bender, Katherine; Hu, Zhenxin; Costello, Alison L.; Bennett, Brian; Tierney, David L.; Crowder, Michael W.

doi:10.1021/ja900296u

Cited by 45 publications

(89 citation statements)

References 57 publications

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“…Positive cooperativity for metal ion binding has also been reported for other B1-type MBLs, i.e. the enzymes CcrA [95]- [99] and IMP-1 [36] [41]- [46]. In contrast, the B1 MBL Bla2 from B. anthracis appears to bind the two Zn(II) in sequential order, leading to the speculation that this enzyme may be active in its mononuclear form under physiological conditions [100].…”

Section: Interactions Between Mbls and Metal Ionsmentioning

confidence: 93%

Metallo-β-Lactamases: A Major Threat to Human Health

Phelan¹,

Miraula²,

Selleck³

et al. 2014

AJMB

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Antibiotic resistance is one of the most significant challenges facing global healthcare. Since the 1940s, antibiotics have been used to fight infections, initially with penicillin and subsequently with various derivatives including cephalosporins, carbapenams and monobactams. A common characteristic of these antibiotics is the four-membered β-lactam ring. Alarmingly, in recent years an increasing number of bacteria have become resistant to these antibiotics. A major strategy employed by these pathogens is to use Zn(II)-dependent enzymes, the metallo-β-lactamases (MBLs), which hydrolyse the β-lactam ring. Clinically useful MBL inhibitors are not yet available. Consequently, MBLs remain a major threat to human health. In this review biochemical properties of MBLs are discussed, focusing in particular on the interactions between the enzymes and the functionally essential metal ions. The precise role(s) of these metal ions is still debated and may differ between different MBLs. However, since they are required for catalysis, their binding site may present an alternative target for inhibitor design.

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Section: Interactions Between Mbls and Metal Ionsmentioning

confidence: 93%

Metallo-β-Lactamases: A Major Threat to Human Health

Phelan¹,

Miraula²,

Selleck³

et al. 2014

AJMB

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“…B1 and B3 MBLs are broad-spectrum enzymes that hydrolyze penicillins, cephalosporins, and carbapenems with a wide variety of in vitro catalytic efficiencies, displaying a broad range of resistance profiles in vivo (1)(2)(3)(4)(5)8). The di-Zn(II) form of B1 MBLs has been shown to be the active form in the bacterial periplasm, despite contradictory data obtained from in vitro studies (8)(9)(10). These enzymes display a conserved metal binding motif, where the coordination sphere of the metal ion in the Zn1 site involves three His residues (3-H site), His116, His118, and His196, and a water/hydroxide molecule (the active nucleophile) in a tetrahedral arrangement, while the metal ion in the Zn2 site adopts a trigonal bipyramidal coordination sphere, with Asp120, Cys221, His263 (DCH site), a water molecule, and the formerly mentioned water/hydroxide molecule as ligands (11)(12)(13)(14)(15) (Fig.…”

mentioning

confidence: 99%

Crystal Structure of the Metallo-β-Lactamase GOB in the Periplasmic Dizinc Form Reveals an Unusual Metal Site

Morán-Barrio

Lisa

Larrieux

et al. 2016

Antimicrob Agents Chemother

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f Metallo-beta-lactamases (MBLs) are broad-spectrum, Zn(II)-dependent lactamases able to confer resistance to virtually every ␤-lactam antibiotic currently available. The large diversity of active-site structures and metal content among MBLs from different sources has limited the design of a pan-MBL inhibitor. GOB-18 is a divergent MBL from subclass B3 that is expressed by the opportunistic Gram-negative pathogen Elizabethkingia meningoseptica. This MBL is atypical, since several residues conserved in B3 enzymes (such as a metal ligand His) are substituted in GOB enzymes. Here, we report the crystal structure of the periplasmic di-Zn(II) form of GOB-18. This enzyme displays a unique active-site structure, with residue Gln116 coordinating the Zn1 ion through its terminal amide moiety, replacing a ubiquitous His residue. This situation contrasts with that of B2 MBLs, where an equivalent His116Asn substitution leads to a di-Zn(II) inactive species. Instead, both the mono-and di-Zn(II) forms of GOB-18 are active against penicillins, cephalosporins, and carbapenems. In silico docking and molecular dynamics simulations indicate that residue Met221 is not involved in substrate binding, in contrast to Ser221, which otherwise is conserved in most B3 enzymes. These distinctive features are conserved in recently reported GOB orthologues in environmental bacteria. These findings provide valuable information for inhibitor design and also posit that GOB enzymes have alternative functions.T he expression of ␤-lactamases is the main mechanism of bacterial resistance against ␤-lactam antibiotics. These enzymes catalyze the hydrolysis of the amide bond in the ␤-lactam ring characteristic of this family of drugs (1-5). MBLs are metal-dependent hydrolases which generally use Zn(II) as a Lewis acid to activate a water molecule for the nucleophilic attack. These enzymes are refractive to clinically employed lactamase inhibitors (1) and have a particular relevance in the clinical setting as they can hydrolyze a broad spectrum of ␤-lactam substrates, being able to inactivate carbapenems, the "last-resort" antibiotics in antibacterial therapy (6).MBLs have been classified into subclasses B1, B2, and B3 based on sequence identity (7). Crystal structures of MBLs from the three subclasses have revealed that these enzymes present a common ␣␤/␤␣ sandwich fold, with the active site located within a groove at the interface between these two halves (1-6). The Zn(II)-binding residues vary among different subclasses, giving rise to diverse metal site architectures and metal contents required for activity (1-6). B1 and B3 MBLs are broad-spectrum enzymes that hydrolyze penicillins, cephalosporins, and carbapenems with a wide variety of in vitro catalytic efficiencies, displaying a broad range of resistance profiles in vivo (1)(2)(3)(4)(5)8). The di-Zn(II) form of B1 MBLs has been shown to be the active form in the bacterial periplasm, despite contradictory data obtained from in vitro studies (8-10). These enzymes display a conserved metal binding m...

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“…The EPR spectra and parameters for AIM-1 are similar to those from NDM-1, Bla2 from Bacillus anthracis and L1 from Stenotrophomonas maltophilia when loaded with two Co 2+ ions (128,233) . In perpendicular mode the cwEPR spectra at 20 K were not saturated (spectrum strength increases linearly with the square root of the microwave power) over the range of microwave power, whereas at 4.5 K the spectrum at the highest microwave power of 20 mW (10dB) is saturated.…”

Section: Spectroscopic Characterisation Of the Aim-1 Active Sitementioning

confidence: 67%

“…from S. maltophilia (128,233) . While Bla2 converts the substrate nitrocefin directly to its corresponding product (i.e.…”

Section: Discussionmentioning

confidence: 99%

“…Pre-steady state kinetic data for the reaction of AIM-1 with the substrate nitrocefin were acquired in order to probe the initial phase of the catalytic cycle, but also to compare the mechanism of action with that of other MBLs, notably Bla2, NDM-1 and L1 (128,233) . The reaction was monitored for 500 ms using a diode array detector ( Figure 5.16, top panel).…”

Section: Rapid Kinetics Measurementsmentioning

confidence: 99%

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Kinetic, mechanistic, structural and spectroscopic investigations of Bimetallic Metallohydrolases

Selleck¹

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Differential Binding of Co(II) and Zn(II) to Metallo-β-Lactamase Bla2 from Bacillus anthracis

Cited by 45 publications

References 57 publications

Metallo-β-Lactamases: A Major Threat to Human Health

Metallo-β-Lactamases: A Major Threat to Human Health

Crystal Structure of the Metallo-β-Lactamase GOB in the Periplasmic Dizinc Form Reveals an Unusual Metal Site

Kinetic, mechanistic, structural and spectroscopic investigations of Bimetallic Metallohydrolases

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