Pseudomonas aeruginosa lipopolysaccharide (LPS) contains two glycoforms of core oligosaccharide (OS); one form is capped with O antigen through an alpha-1,3-linked L-rhamnose (L-Rha), while the other is uncapped and contains an alpha-1,6-linked L-Rha. Two genes in strain PAO1, wapR (PA5000) and migA (PA0705), encode putative glycosyltransferases associated with core biosynthesis. We propose tha...

The waa gene cluster is responsible for the biosynthesis of the lipopolysaccharide (LPS) core region in Escherichia coli and Salmonella: Homologs of the waaZ gene product are encoded by the waa gene clusters of Salmonella enterica and E. coli strains with the K-12 and R2 core types. Overexpression of WaaZ in E. coli and S. enterica led to a modified LPS structure showing core truncations and (w...

Lipopolysaccharide (LPS) expressed by isolates of Pseudomonas aeruginosa from cystic fibrosis patients lacks the O-polysaccharide chain but the degree to which the rest of the molecule changes has not been determined. We analyzed, for the first time, the core structure of an LPS from a rough, cystic fibrosis isolate of P. aeruginosa. The products of mild acid hydrolysis and strong alkaline degr...

The binding of spike H and G proteins of bacteriophage PX174 with lipopolysaccharides (LPSs) were evaluated by a competitive enzyme-linked plate assay using the biotin-labeled LPS of Escherichia coli C, one of a host strain, and the non-labeled LPSs having different R-core polysaccharide lengths. H protein promptly decreased its affinity when some saccharide residues were truncated from the out...

Lipopolysaccharide (LPS) is essential for most gram-negative bacteria and plays an important role in serum resistance, pathogenesis, drug protection from harsh environments. The outer core oligosaccharide of LPS involved bacterial recognition invasion host cells. D-galactosyltransferase WaaB responsible the addition D-galactose to LPS, which Salmonella typhimurium invasion. Here we report first...

Understanding the electrostatic interactions between bacterial membranes and exogenous proteins is crucial to designing effective antimicrobial agents against Gram-negative bacteria. Here we study, using neutron reflecometry under multiple isotopic contrast conditions, the role of the uncharged sugar groups in the outer core region of lipopolysaccharide (LPS) in protecting the phosphate-rich in...

Lipopolysaccharide (LPS) is essential for the vitality of most Gram-negative bacteria and plays an important role in bacterial multidrug resistance. The LptD/E translocon inserts LPS into the outer leaflet, the mechanism of which is poorly understood. Here, we report mutagenesis, functional assays, and molecular dynamics simulations of the LptD/E complex, which suggest two distinct pathways for...

The outer membrane of Gram-negative bacteria is a unique asymmetric lipid bilayer composed of phospholipids (PLs) in the inner leaflet and lipopolysaccharides (LPSs) in the outer leaflet. Its function as a selective barrier is crucial for the survival of bacteria in many distinct environments, and it also renders Gram-negative bacteria more resistant to antibiotics than their Gram-positive coun...

Actins are cytoskeletal proteins that regulate cell motility. Cellular actins of various species have very similar immunological and physical properties. Actins are highly conserved proteins that are involved in cell motility, structure and integrity. Alpha actins are a major constituent of the contractile apparatus. Alpha-smooth muscle actin (α-SMA) is commonly used as a marker of myofibroblas...

Lipopolysaccharides (LPS), major virulence determinants in Gram-negative bacteria, are responsible for many pathophysiological responses and can elicit strong immune responses. In order to better understand the role of LPS in host-pathogen interactions and elucidate the immunogenic properties of LPS outer core oligosaccharides, an all α-linked Escherichia coli R3 outer core pentasaccharide was ...