Molecular analysis of beta-lactamase structure and function

Majiduddin, Fahd K.; Materon, Isabel C.; Palzkill, Timothy

doi:10.1078/1438-4221-00198

Cited by 147 publications

(127 citation statements)

References 79 publications

Supporting

Mentioning

121

Contrasting

Unclassified

Order By: Relevance

“…On the basis of their different catalytic mechanisms, two groups have been established whereby class B enzymes are metalloproteins that require zinc for their activity, and class A, C, and D ␤-lactamases contain serine groups in their active site (4). Oxacillinases are Ambler class D ␤-lactamases with hydrolytic activity against penicillins, extendedspectrum cephalosporins, methicillin, and aztreonam (5).…”

mentioning

confidence: 99%

Crystal structure of the carbapenemase OXA-24 reveals insights into the mechanism of carbapenem hydrolysis

Santillana

Beceiro

Bou

et al. 2007

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

106

162

View full text Add to dashboard Cite

Combating bacterial resistance to ␤-lactams, the most widely used antibiotics, is an emergent and clinically important challenge. OXA-24 is a class D ␤-lactamase isolated from a multiresistant epidemic clinical strain of Acinetobacter baumannii. We have investigated how OXA-24 specifically hydrolyzes the last resort carbapenem antibiotic, and we have determined the crystal structure of OXA-24 at a resolution of 2.5 Å. The structure shows that the carbapenem's substrate specificity is determined by a hydrophobic barrier that is established through the specific arrangement of the Tyr-112 and Met-223 side chains, which define a tunnel-like entrance to the active site. The importance of these residues was further confirmed by mutagenesis studies. Biochemical and microbiological analyses of specific point mutants selected on the basis of structural criteria significantly reduced the catalytic efficiency (kcat/Km) against carbapenems, whereas the specificity for oxacillin was noticeably increased. This is the previously unrecognized crystal structure that has been obtained for a class D carbapenemase enzyme. Accordingly, this information may help to improve the development of effective new drugs to combat ␤-lactam resistance. More specifically, it may help to overcome carbapenem resistance in A. baumannii, probably one of the most worrying infectious threats in hospitals worldwide.␤-lactamases ͉ carbapenem resistance ͉ enzyme mechanism ͉ protein crystallography ͉ Acinetobacter baumannii

show abstract

mentioning

confidence: 99%

Crystal structure of the carbapenemase OXA-24 reveals insights into the mechanism of carbapenem hydrolysis

Santillana

Beceiro

Bou

et al. 2007

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

106

162

View full text Add to dashboard Cite

show abstract

“…The TEM-1 b-lactamase has been the subject of extensive experimental investigations into the determinants of enzyme structure and function. 6,7 Structural information on acylated versions of TEM-1 b-lactamase as well as the Arg244Ser inhibitor resistant TEM-30 enzyme indicate that Arg244 forms hydrogen bonds with the carboxylate group common to both penicillins and cephalosporins. 8,9 In addition, site-directed mutagenesis and enzyme kinetic characterization as well as molecular dynamics simulation studies indicate that the interaction of the Arg244 guanidinium group with the carboxyl group of the antibiotic is important for both substrate and inhibitor binding.…”

mentioning

confidence: 99%

Analysis of the plasticity of location of the Arg244 positive charge within the active site of the TEM‐1 β‐lactamase

2009

View full text Add to dashboard Cite

A large number of b-lactamases have emerged that are capable of conferring bacterial resistance to b-lactam antibiotics. Comparison of the structural and functional features of this family has refined understanding of the catalytic properties of these enzymes. An arginine residue present at position 244 in TEM-1 b-lactamase interacts with the carboxyl group common to penicillin and cephalosporin antibiotics and thereby stabilizes both the substrate and transition state complexes. A comparison of class A b-lactamase sequences reveals that arginine at position 244 is not conserved, although a positive charge at this structural location is conserved and is provided by an arginine at positions 220 or 276 for those enzymes lacking arginine at position 244. The plasticity of the location of positive charge in the b-lactamase active site was experimentally investigated by relocating the arginine at position 244 in TEM-1 b-lactamase to positions 220, 272, and 276 by site-directed mutagenesis. Kinetic analysis of the engineered b-lactamases revealed that removal of arginine 244 by alanine mutation reduced catalytic efficiency against all substrates tested and restoration of an arginine at positions 272 or 276 partially suppresses the catalytic defect of the Arg244Ala substitution. These results suggest an evolutionary mechanism for the observed divergence of the position of positive charge in the active site of class A b-lactamases.

show abstract

“…Chromosomally mediated, inducible ␤-lactamases were recognized as the major mechanism of ␤-lactam resistance in Aeromonas hydrophila. These enzymes comprise a molecular class C cephalosporinase, a class D penicillinase, and a class B metallo-␤-lactamase (MBL) designated CphA, the last being a carbapenemase enzyme with a relatively narrow substrate profile (1,16,19,20). In this report we describe the first VIM MBL-producing A. hydrophila strain carrying an integron-borne bla VIM-4 gene.…”

mentioning

confidence: 99%

Identification of the First VIM Metallo-β-Lactamase-Producing Multiresistant Aeromonas hydrophila Strain

et al. 2008

View full text Add to dashboard Cite

A VIM metallo-␤-lactamase-producing Aeromonas hydrophila strain carrying an integron-borne bla VIM-4 gene was isolated from a cirrhotic patient's fecal sample in a Budapest hospital. The variable region of this integron is identical with that of a previously characterized integron from Pseudomonas aeruginosa clinical isolates in Pécs in southern Hungary.Aeromonas species are considered food-borne pathogens of emerging importance (2,7,15). Most species belonging to this genus, particularly those associated with human infections, are widely distributed in the environment, especially in freshwater, sewage, marine environments, and drinking water, and are also found in a wide range of animal and plant food products (1, 2, 5, 21). These pathogens can cause infections in both immunocompetent and -compromised patients, including gastroenteritis, bacteremia, meningitis, and skin and soft-tissue infections (9). Chromosomally mediated, inducible ␤-lactamases were recognized as the major mechanism of ␤-lactam resistance in Aeromonas hydrophila. These enzymes comprise a molecular class C cephalosporinase, a class D penicillinase, and a class B metallo-␤-lactamase (MBL) designated CphA, the last being a carbapenemase enzyme with a relatively narrow substrate profile (1,16,19,20). In this report we describe the first VIM MBL-producing A. hydrophila strain carrying an integron-borne bla VIM-4 gene.Antimicrobial disk susceptibility tests were performed on Mueller-Hinton agar (Oxoid, Basingstoke, United Kingdom) as recommended by the Clinical and Laboratory Standards Institute (6). Test disks were purchased from Oxoid. MICs were determined by the agar dilution method for ␤-lactam antibiotics and by the Etest (AB Biodisk, Solna, Sweden) for other antibiotics. To detect MBL production, the MBL Etest (AB Biodisk, Solna, Sweden) and the imipenem-EDTA disk method (23) were used and complemented with the use of ceftazidime, cefepime, cefotaxime, cefoxitin, cefoperazone, piperacillin, and piperacillin-tazobactam disks with or without 750 g EDTA. To prepare ␤-lactam-EDTA disks, 750 g EDTA in the form of a 0.5 M EDTA solution (pH 8.0) was added to a ␤-lactam disk placed on a Mueller-Hinton agar plate (3, 23).Detection of bla VIM genes and class 1 integrons by PCR and sequencing was performed as described earlier (13,14). Conjugation experiments were performed on Mueller-Hinton agar plates with the Escherichia coli J5-3 Rif r and Pseudomonas aeruginosa PAO4089Rp strains (12) as recipients. Transconjugants were selected on Mueller-Hinton agar plates containing 300 and 100 g/ml rifampin, respectively, and 32 g/ml cefotaxime or 128 g/ml ticarcillin.

show abstract

Molecular analysis of beta-lactamase structure and function

Cited by 147 publications

References 79 publications

Crystal structure of the carbapenemase OXA-24 reveals insights into the mechanism of carbapenem hydrolysis

Crystal structure of the carbapenemase OXA-24 reveals insights into the mechanism of carbapenem hydrolysis

Analysis of the plasticity of location of the Arg244 positive charge within the active site of the TEM‐1 β‐lactamase

Identification of the First VIM Metallo-β-Lactamase-Producing Multiresistant Aeromonas hydrophila Strain

Contact Info

Product

Resources

About