Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
Add more filters










Database
Language
Publication year range
1.
PLoS One ; 8(4): e60754, 2013.
Article in English | MEDLINE | ID: mdl-23593301

ABSTRACT

We identified an essential cell wall biosynthetic enzyme in Bacillus anthracis and an inhibitor thereof to which the organism did not spontaneously evolve measurable resistance. This work is based on the exquisite binding specificity of bacteriophage-encoded cell wall-hydrolytic lysins, which have evolved to recognize critical receptors within the bacterial cell wall. Focusing on the B. anthracis-specific PlyG lysin, we first identified its unique cell wall receptor and cognate biosynthetic pathway. Within this pathway, one biosynthetic enzyme, 2-epimerase, was required for both PlyG receptor expression and bacterial growth. The 2-epimerase was used to design a small-molecule inhibitor, epimerox. Epimerox prevented growth of several Gram-positive pathogens and rescued mice challenged with lethal doses of B. anthracis. Importantly, resistance to epimerox was not detected (<10(-11) frequency) in B. anthracis and S. aureus. These results describe the use of phage lysins to identify promising lead molecules with reduced resistance potential for antimicrobial development.


Subject(s)
Anti-Infective Agents/pharmacology , Bacteriophages/metabolism , Mucoproteins/metabolism , Animals , Bacillus anthracis/drug effects , Bacillus anthracis/growth & development , DNA Primers , Female , Mice , Mice, Inbred C57BL , Microbial Sensitivity Tests , Polymerase Chain Reaction
2.
ACS Med Chem Lett ; 4(12): 1142-1147, 2013 Dec 12.
Article in English | MEDLINE | ID: mdl-24443700

ABSTRACT

We present the discovery and optimization of a novel series of inhibitors of bacterial UDP-N-acetylglucosamine 2-epimerase (called 2-epimerase in this paper). Starting from virtual screening hits, the activity of various inhibitory molecules was optimized using a combination of structure-based and rational design approaches. We successfully designed and identified a 2-epimerase inhibitor (compound 12-ES-Na, that we named Epimerox) which blocked the growth of methicillin-resistant Staphylococcus aureus (MRSA) at 3.9 µM MIC (minimum inhibitory concentration) and showed potent broad-range activity against all Gram-positive bacteria that were tested. Additionally a microplate coupled assay was performed to further confirm that the 2-epimerase inhibition of Epimerox was through a target-specific mechanism. Furthermore, Epimerox demonstrated in vivo efficacy and had a pharmacokinetic profile that is consonant with it being developed into a promising new antibiotic agent for treatment of infections caused by Gram-positive bacteria.

3.
Acta Crystallogr D Biol Crystallogr ; 68(Pt 12): 1613-21, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23151626

ABSTRACT

SseI is secreted into host cells by Salmonella and contributes to the establishment of systemic infections. The crystal structure of the C-terminal domain of SseI has been solved to 1.70 Å resolution, revealing it to be a member of the cysteine protease superfamily with a catalytic triad consisting of Cys178, His216 and Asp231 that is critical to its virulence activities. Structure-based analysis revealed that SseI is likely to possess either acyl hydrolase or acyltransferase activity, placing this virulence factor in the rapidly growing class of enzymes of this family utilized by bacterial pathogens inside eukaryotic cells.


Subject(s)
Salmonella/metabolism , Virulence Factors/metabolism , Virulence , Amino Acid Sequence , Catalytic Domain , Cloning, Molecular , Crystallization , Models, Molecular , Molecular Sequence Data , Protein Conformation , Proteolysis , Salmonella/pathogenicity , Virulence Factors/chemistry , Virulence Factors/genetics , Virulence Factors/isolation & purification
4.
EMBO Rep ; 9(2): 199-205, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18188181

ABSTRACT

The non-hydrolysing bacterial UDP-N-acetylglucosamine 2-epimerase (UDP-GlcNAc 2-epimerase) catalyses the conversion of UDP-GlcNAc into UDP-N-acetylmannosamine, an intermediate in the biosynthesis of several cell-surface polysaccharides. This enzyme is allosterically regulated by its substrate UDP-GlcNAc. The structure of the ternary complex between the Bacillus anthracis UDP-GlcNAc 2-epimerase, its substrate UDP-GlcNAc and the reaction intermediate UDP, showed direct interactions between UDP and its substrate, and between the complex and highly conserved enzyme residues, identifying the allosteric site of the enzyme. The binding of UDP-GlcNAc is associated with conformational changes in the active site of the enzyme. Kinetic data and mutagenesis of the highly conserved UDP-GlcNAc-interacting residues confirm their importance in the substrate binding and catalysis of the enzyme. This constitutes the first example to our knowledge, of an enzymatic allosteric activation by direct interaction between the substrate and the allosteric activator.


Subject(s)
Bacillus anthracis/enzymology , Allosteric Regulation , Bacillus anthracis/growth & development , Binding Sites , Carbohydrate Conformation , Carbohydrate Epimerases/chemistry , Carbohydrate Epimerases/metabolism , Catalysis , Crystallography, X-Ray , Hydrolysis , Kinetics , Models, Molecular , Protein Conformation , Structure-Activity Relationship , Substrate Specificity , Uridine Diphosphate N-Acetylglucosamine/chemistry , Uridine Diphosphate N-Acetylglucosamine/metabolism
5.
Cell Host Microbe ; 1(4): 241-3, 2007 Jun 14.
Article in English | MEDLINE | ID: mdl-18005702

ABSTRACT

Many animal models of bacterial diseases are hampered by differences in tissue tropism and the course of pathogenesis. In a recent issue of Cell, by rationally mutating a surface invasion protein (InlA) to have higher binding affinity for its cognate host receptor (E-cadherin), Wollert et al. were able to "murinize"Listeria monocytogenes, creating a strain capable of invading intestinal epithelial cells in mice, mimicking the route of infection in humans.


Subject(s)
Anti-Infective Agents/chemical synthesis , Chemical Engineering/methods , Designer Drugs/chemical synthesis , Infections , Animals , Anti-Bacterial Agents/chemical synthesis , Cadherins/physiology , Designer Drugs/chemistry , Disease Models, Animal , Humans , Listeria/drug effects , Mice
SELECTION OF CITATIONS
SEARCH DETAIL
...