Beta-Lactamases and DD-Peptidases: Active Site Chemistry

Summary

Principal Investigator: REX PRATT
Abstract: Project Summary Bacterial resistance to [unreadable]-lactam antibiotics continues to become more prevalent and more clinically important. A large part of the resistance can be understood and investigated experimentally in terms of the chemistry of the interactions of [unreadable]-lactam antibiotics with the active sites of two groups of bacterial enzymes, the [unreadable]lactamases on one hand, which catalyze the hydrolysis of the antibiotics, and the D-alanyl-D-alanine transpeptidase/carboxypeptidases on the other, which catalyze the synthesis and maintenance of the peptide cross-links of bacterial cell walls, and which are inhibited by [unreadable]-lactam antibiotics. There is now good reason to believe that all of these [unreadable]-lactam binding sites have much in common. An understanding of the structure and function of these sites and of the relationship between them is fundamental to future antibiotics design - both [unreadable]lactam and otherwise. The object of the proposed research is to explore further the chemical functionality and the substrate binding properties of a series of these active sites, using a number of modified substrates, novel inhibitors and potential effectors. Particular focus will be on the development of ligands, substrate and inhibitors, for the transpeptidases which, to date, have exhibited little in vivo activity except with [unreadable]-lactams. The specificity of these enzymes for peptidoglycan structural motifs will be examined closely. Crystal structures will be used in conjunction with molecular modeling to interpret the results obtained and apply them to further ligand design. These studies will lead to new insight into the chemistry of [unreadable]-lactamase and transpeptidase active sites, and thus to new directions in antibiotic design.
Funding Period: 1982-09-30 - 2009-07-31
more information: NIH RePORT

Top Publications

  1. pmc Crystal structures of complexes of bacterial DD-peptidases with peptidoglycan-mimetic ligands: the substrate specificity puzzle
    Eric Sauvage
    Centre d Ingéniere des Proteines, Universite de Liege, B 4000 Sart Tilman, Liege, Belgium
    J Mol Biol 381:383-93. 2008
  2. pmc Kinetics and mechanism of inhibition of a serine beta-lactamase by O-aryloxycarbonyl hydroxamates
    Ryan B Pelto
    Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, USA
    Biochemistry 47:12037-46. 2008
  3. pmc Substituted aryl malonamates as new serine beta-lactamase substrates: structure-activity studies
    S A Adediran
    Department of Chemistry, Wesleyan University, Middletown, CT 06459, USA
    Bioorg Med Chem 18:282-91. 2010
  4. pmc Crossover inhibition as an indicator of convergent evolution of enzyme mechanisms: a β-lactamase and a N-terminal nucleophile hydrolase
    S A Adediran
    Department of Chemistry, Wesleyan University, Middletown, CT 06459, USA
    FEBS Lett 586:4186-9. 2012
  5. pmc Inhibition of DD-peptidases by a specific trifluoroketone: crystal structure of a complex with the Actinomadura R39 DD-peptidase
    Liudmila Dzhekieva
    Department of Chemistry, Wesleyan University, Lawn Avenue, Middletown, Connecticut 06459, United States
    Biochemistry 52:2128-38. 2013

Detail Information

Publications5

  1. pmc Crystal structures of complexes of bacterial DD-peptidases with peptidoglycan-mimetic ligands: the substrate specificity puzzle
    Eric Sauvage
    Centre d Ingéniere des Proteines, Universite de Liege, B 4000 Sart Tilman, Liege, Belgium
    J Mol Biol 381:383-93. 2008
    ..This striking deficiency may represent a sophisticated defense mechanism against low-molecular-mass substrate-analogue inhibitors/antibiotics; its discovery should focus new inhibitor design...
  2. pmc Kinetics and mechanism of inhibition of a serine beta-lactamase by O-aryloxycarbonyl hydroxamates
    Ryan B Pelto
    Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, USA
    Biochemistry 47:12037-46. 2008
    ..Such an alternative mode of reaction may lead to the design of novel inhibitors...
  3. pmc Substituted aryl malonamates as new serine beta-lactamase substrates: structure-activity studies
    S A Adediran
    Department of Chemistry, Wesleyan University, Middletown, CT 06459, USA
    Bioorg Med Chem 18:282-91. 2010
    ..These results, therefore, provide further evidence for the covalent access of compounds bearing retro-amide side chains to the active sites of beta-lactam-recognizing enzymes...
  4. pmc Crossover inhibition as an indicator of convergent evolution of enzyme mechanisms: a β-lactamase and a N-terminal nucleophile hydrolase
    S A Adediran
    Department of Chemistry, Wesleyan University, Middletown, CT 06459, USA
    FEBS Lett 586:4186-9. 2012
    ..It is likely that a mechanistic imperative has led to convergent evolution of these enzyme active sites, of a β-lactam-recognizing enzyme and a N-terminal protease belonging to different amidohydrolase superfamilies...
  5. pmc Inhibition of DD-peptidases by a specific trifluoroketone: crystal structure of a complex with the Actinomadura R39 DD-peptidase
    Liudmila Dzhekieva
    Department of Chemistry, Wesleyan University, Lawn Avenue, Middletown, Connecticut 06459, United States
    Biochemistry 52:2128-38. 2013
    ..The trifluoroketone moiety, therefore, should be considered along with boronic acids and phosphonates as a warhead that can be incorporated into new and effective DD-peptidase inhibitors and therefore, perhaps, antibiotics...