Purification and properties of inducible penicillin beta-lactamase isolated from Pseudomonas maltophilia

Saino, Yushi; Kobayashi, Fujio; Inoue, Matsuhisa; Mitsuhashi, Susumu

doi:10.1128/aac.22.4.564

Cited by 227 publications

(166 citation statements)

References 30 publications

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“…Stability of the L1 Tetramer Structure-L1 is unique among ␤-lactamases in that the functional enzyme is a tetramer (5,30,31). A number of interactions are predicted to be involved in the stability of the tetramer structure, including those involving amino acids at the N terminus (30).…”

Section: Discussionmentioning

confidence: 99%

“…(i) The functional enzyme is a tetramer (5,30,31). (ii) Its monomer is 4 -5 kDa larger than the others.…”

mentioning

confidence: 99%

“…S. maltophilia is inherently resistant to most antibacterial drugs, including most, if not all, ␤-lactams (3,4). ␤-Lactam resistance in this organism is mainly mediated by the inducible expression of two ␤-lactamases (designated L1 and L2) (5,6). These are bacterial enzymes that hydrolyze ␤-lactam antibiotics, rendering them ineffective as inhibitors of bacterial cell wall synthesis (7).…”

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confidence: 99%

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Characterization of Monomeric L1 Metallo-β-lactamase and the Role of the N-terminal Extension in Negative Cooperativity and Antibiotic Hydrolysis

Simm¹,

Higgins²,

Carenbauer³

et al. 2002

Journal of Biological Chemistry

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The L1 metallo-␤-lactamase from Stenotrophomonas maltophilia is unique among this class of enzymes because it is tetrameric. Previous work predicted that the two regions of important intersubunit interaction were the residue Met-140 and the N-terminal extensions of each subunit. The N-terminal extension was also implicated in ␤-lactam binding. Mutation of methionine 140 to aspartic acid results in a monomeric L1 ␤-lactamase with a greatly altered substrate specificity profile. A 20-amino acid N-terminal deletion mutant enzyme (NDel) could be isolated in a tetrameric form but demonstrated greatly reduced rates of ␤-lactam hydrolysis and different substrate profiles compared with that of the parent enzyme. Specific site-directed mutations of individual N terminus residues were made (Y11S, W17S, and a double mutant L5A/L8A). All N-terminal mutant enzymes were tetramers and all showed higher K m values for ampicillin and nitrocefin, hydrolyzed ceftazidime poorly, and hydrolyzed imipenem more efficiently than ampicillin in contrast to wild-type L1. Nitrocefin turnover was significantly increased, probably because of an increased rate of breakdown of the intermediate species due to a lack of stabilizing forces. K m values for monomeric L1 were greatly increased for all antibiotics tested. A model of a highly mobile N-terminal extension in the monomeric enzyme is proposed to explain these findings. Tetrameric L1 shows negative cooperativity, which is not present in either the monomer or N-terminal deletion enzymes, suggesting that the cooperative effect is mediated via N-terminal intersubunit interactions. These data indicate that while the N terminus of L1 is not essential for ␤-lactam hydrolysis, it is clearly important to its activity and substrate specificity.

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Section: Discussionmentioning

confidence: 99%

“…(i) The functional enzyme is a tetramer (5,30,31). (ii) Its monomer is 4 -5 kDa larger than the others.…”

mentioning

confidence: 99%

mentioning

confidence: 99%

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Characterization of Monomeric L1 Metallo-β-lactamase and the Role of the N-terminal Extension in Negative Cooperativity and Antibiotic Hydrolysis

Simm¹,

Higgins²,

Carenbauer³

et al. 2002

Journal of Biological Chemistry

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“…Thus, mutant strains with basal expression of this enzyme, whether expression was inducible or basal for L2 /?-lactamase, were exquisitely susceptible to meropenem (MIC 0. 5 and moderately so to imipenem (MIC 4-16 mg/L). Inducible j3-lactamase expression gave some protection against third-generation cephalosporins, piperacillin and carbenicillin but constitutive hyperproduction (in mutant strains 7-con, 8-con, 8-con* and 9-con) gave greater resistance.…”

Section: Discussionmentioning

confidence: 99%

Susceptibility to -lactam antibiotics of mutant strains of Xanthomonas maltophilia with high- and low-level constitutive expression of L1 and L2 -lactamases

Akova

Bonfiglio²,

Livermore³

1991

Journal of Medical Microbiology

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Summary. Xanthomonas maltophilia produces two inducible P-lactamases, L 1 and L2, and resists the antimicrobial activity of P-lactam antibiotics, including carbapenems. L1 is a zinc-metaloenzyme with carbapenemase activity; L2 is an unusual cephalosporinase. Mutant strains with high-and low-level constitutive expression of these enzymes were derived from three reference strains of X. maltophilia. With a single exception, the mutant strains had altered expression of both enzymes, indicating that these P-lactamases share regulatory components. The exception was a mutant strain that had low-level constitutive (basal) expression of L1 enzyme but remained inducible for L2. A parent strain with low-level Blactamase inducibility was more susceptible to penicillins, cephalosporins and carbapenems than were those in which higher levels of enzyme activity were inducible. Mutations that caused high-level constitutive P-lactamase expression increased resistance to penicillins and newer cephalosporins. P-Lactamase basal mutant strains, including the one that remained inducible for L2 enzyme, were more susceptible than inducible strains to these drugs. Organisms with inducible or high-level constitutive P-lactamase expression were equally resistant to meropenem and imipenem but basal mutant strains, including the one that remained inducible for L2 enzyme, were more susceptible to meropenem than imipenem. Minimal inhibitory concentrations of meropenem, penicillins and cephalosporins, but not imipenem, were greater on Mueller Hinton agar than on IsoSensitest or Diagnostic Sensitivity Test agars. This behaviour was independent of P-lactamase inducibility, and may reflect permeability differences between cells grown on different media.

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“…A segunda MβL foi descrita em 1982 em Stenotrophomonas maltophilia (Saino et al, 1982). Osano et al (1994) relatou o primeiro caso de MßL adquirida, descrevendo IMP-1 como uma nova subclasse.…”

Section: Metalo-beta-lactamases (Mβl)unclassified

Alternativas terapêuticas para o tratamento de infecções por Pseudomonas aeruginosa multirresistentes endêmicas no Brasil.

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Purification and properties of inducible penicillin beta-lactamase isolated from Pseudomonas maltophilia

Cited by 227 publications

References 30 publications

Characterization of Monomeric L1 Metallo-β-lactamase and the Role of the N-terminal Extension in Negative Cooperativity and Antibiotic Hydrolysis

Characterization of Monomeric L1 Metallo-β-lactamase and the Role of the N-terminal Extension in Negative Cooperativity and Antibiotic Hydrolysis

Susceptibility to -lactam antibiotics of mutant strains of Xanthomonas maltophilia with high- and low-level constitutive expression of L1 and L2 -lactamases

Alternativas terapêuticas para o tratamento de infecções por Pseudomonas aeruginosa multirresistentes endêmicas no Brasil.

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