Ahmed El Zoeiby

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The biogenesis of biological membranes hinges on the coordinated trafficking of membrane lipids between distinct cellular compartments. The bacterial outer membrane enzyme PagP confers resistance to host immune defenses by transferring a palmitate chain from a phospholipid to the lipid A (endotoxin) component of lipopolysaccharide. PagP is an eight-stranded(More)
MurM is an aminoacyl ligase that adds l-serine or l-alanine as the first amino acid of a dipeptide branch to the stem peptide lysine of the pneumococcal peptidoglycan. MurM activity is essential for clinical pneumococcal penicillin resistance. Analysis of peptidoglycan from the highly penicillin-resistant Streptococcus pneumoniae strain 159 revealed that in(More)
Bacterial peptidoglycan is the cell wall component responsible for maintaining cell integrity against osmotic pressure. Biosynthesis of the cytoplasmic precursor UDP-N-acetylmuramyl pentapeptide is catalyzed by the Mur enzymes. Genomic analysis of the three regions encoding Mur proteins was achieved. We have cloned and over-expressed the murA, -B, -D, -E(More)
We cloned and sequenced the murC gene from Pseudomonas aeruginosa encoding a protein of 53 kDa. Multiple alignments with 20 MurC peptide sequences from different bacteria confirmed the presence of highly conserved regions having sequence identities ranging from 22-97% including conserved motifs for ATP-binding and the active site of the enzyme. Genetic(More)
One of the biggest challenges for recent medical research is the continuous development of new antibiotics interacting with bacterial essential mechanisms. The machinery for peptidoglycan biosynthesis is a rich source of crucial targets for antibacterial chemotherapy. The cytoplasmic steps of the biosynthesis of peptidoglycan precursor, catalysed by a(More)
The enzymology of palmitate addition to lipid A can be traced to the early discovery of monosaccharide lipid A precursors, but the functional importance of lipid A palmitoylation in bacterial resistance to the host immune response has emerged only recently. Lipid A palmitoylation in enterobacteria is determined by a PhoP/PhoQ-activated gene pagP, which(More)
The presence of palmitate in a minor fraction of lipid A has been known since the chemical structure of lipid A was first elucidated, but the functional importance in bacterial pathogenesis of regulated lipid A palmitoylation has become clear only recently. A palmitate chain from a phospholipid is incorporated into lipid A by an outer membrane enzyme PagP.(More)
We have developed a screening assay by thin-layer chromatography (TLC) to identify inhibitors for the bacterial essential enzymes MurA, -B, and -C. Libraries of compounds were synthesized using the mix-and-split combinatorial chemistry approach. Screening of the pooled compounds using the developed assay revealed the presence of many pools active in vitro.(More)
OBJECTIVES The machinery of peptidoglycan biosynthesis is an ideal site at which to look for novel antimicrobial targets. Phage display was used to develop novel peptide inhibitors for MurC, an essential enzyme involved in the early steps of biosynthesis of peptidoglycan monomer. METHODS We cloned and overexpressed the murA, -B and -C genes from(More)
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