Gram-negative bacteria constituent

Upon treatment with n-BruiNF, product 97 is converted to 98, which is a key intermediate for the synthesis of the monosaccharide 3-deoxy-D-manno-2-octulosonic acid (KDO)—an essential constituent of the outer membrane lip-op oly s accharide (LPS) of gram-negative bacteria.40... 

The interaction between melittin (a 26 a.a. peptide that exhibits potent anti-microbial activity)90 92 and lipopolysaccharides (the major constituent of the outer membrane of the Gram-negative bacteria) has been studied by NMR. It was demonstrated that the C-terminus of melittin adopts a helical structure in the complex with LPS, while the Y-terminus appears in an extended conformation. STD experiments permitted to identify those residues of melittin in close proximity with LPS, which appeared to be located at the C-terminus and thus, engaged in the formation of helical structure. 

The 3-deoxy-D-ma/ino-2-octulosonic acid 8-phosphate synthase (KDO synthase or KdoS EC 4.1.2.16) is an enzyme involved in the biosynthesis of the eight-carbon sugar KDO [63], a constituent of the capsular polysaccharides (K-antigens) and outer membrane lipopolysaccharides (LPS, endotoxin) of Gram-negative bacteria [156], as well as of the cell wall of algae and a variety of plants [157], In vivo, the enzyme catalyzes the irreversible addition of 26 to D-arabinose 5-phosphate (Ara5P, 32) to form KDO 8-phosphate 33 [158]. The... 

The amino pentose identified (14) in the lipid A constituents of several other species of Gram-negative bacteria was not encountered in these Pseudomonas lipopolysaccharides. 

A further important constituent of human milk, which is not present in formula milk, is lactoferrin, which complexes iron in milk so reducing the iron available for gram-negative bacteria to multiply in the infant gut. 

Antibacterial activity of extracts and isolated constituents of P. sidoides was evaluated against three gram-positive and five gram-negative bacteria (707). Most compounds exhibited antibacterial activities. Further investigations complement these findings 108). 

These two deoxy sugars are the rare monosaccharides that are in the u-configuration. u-Rhamnose is a constituent of lipopolysaccharides of the outer membrane layer of gram-negative bacteria. L-Fucose is a constituent of glycoproteins in cell membranes. 

Structure similar to that of eukaryotes and a thick, bagshaped cell wall. The cell wall, about 25 nm wide, consists of peptidoglycans (Figure 11-14) and polyol phosphate polymers known as teichoic acids. Gram-negative bacteria (e.g., Escherichia coli and Salmonella typhimurium) do not contain teichoic acids but have an outer membrane system external to the plasma membrane and the peptidoglycan. The constituents of this second outer... 

Endotoxin is part of the outer membrane of gram-negative bacteria, found ubiquitously in nature, being present in most indoor environments as a constituent of house dust. It has been suggested that endotoxin levels increase where animals are kept indoors and it seems noteworthy that two recent cross-sectional studies have shown a protective effect of early exposure to cats and dogs on the development of IgE sensitisation [146(111), 208(IIIC)]. However in a prospective birth cohort study in Boston a reduced risk of wheezing was shown in children whose mothers did not have asthma, but an increased risk in children whose mothers had asthma [209(IIIC)]. 

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