Structural studies on the non‐toxic lipid A from Rhodopseudomonas sphaeroides ATCC 17023

Abstract

The lipid A isolated from Rhodopseudomonas sphaeroides ATCC 17023 has been investigated. A sequence of analyses indicated fl-D-glucosaminyl-I ,6-~-glucosamine as the sugar backbone carrying phosphate groups at C-I of the reducing glucosamine and C-4 of the non-reducing glucosamine. Both 3-(7-tetradecenoyl)oxytetradecanoic and 3-oxotetradecanoic acid are linked to the NH2 groups. Two residues of 3-hydroxydecanoic acid are linked to hydroxy groups at C-3 of both reducing and non-reducing glucosamine, and the hydroxy group of 3-hydroxydecanoic acid is free. In free lipid A, the hydroxy group at C-4 of the reducing glucosamine and at C-6 of the non-reducing glucosamine are unsubstituted. The latter probably arises from a 3-deoxy-~-manno-octulosonate linkage.The structural similarities and dissimilarities existing between lipid A of R. sphaeroides, which is non-toxic, and lipid A types such as those from Salmonella, which are toxic, are discussed. Of special interest are the naturally occurring lipid A types that have chemical compositions close to that of toxic Dedicated to Professor Dr Otto Westphal on the occasion of his 70th birthday (February 1, 1983).

Acyl-acyl carrier protein specificity of UDP-GlcNAc acyltransferases from gram-negative bacteria: relationship to lipid A structure

“…In members of the family Enterobacteriaceae, such as Escherichia coli (16,25), Salmonella typhimurium (24), Proteus mirabilis (20), and Serratia marcescens (1), R-3-hydroxymyristoyl moieties are found in the 2,2' (N-linked) and 3,3' (0-linked) positions of the glucosamine disaccharide. In other gram-negative organisms, such as Pseudomonas aeruginosa (9), Rhodobacter (Rhodopseudomonas) sphaeroides (15,19), and Neisseria gonorrhoeae (23), the 0-and N-linked fatty acids have been found to differ. Another member of the Neisseria-Moraxella family, Acinetobacter calcoaceticus, has been reported to contain 0-and N-linked 3-hydroxylaurate (27).…”

Key structures of bacterial peptidoglycan and lipopolysaccharide triggering the innate immune system of higher animals: Chemical synthesis and functional studies

“…New possibilities became realistic to find antagonistic compounds to be used clinically to suppress the toxic effects of LPS. Additional examples of antagonistic lipid A were then discovered from other bacterial species by other research groups, 52) , 53) which led to chemical synthesis of artificial antagonistic molecules to be of possible value in clinical application against bacterial sepsis. 54) , 55) …”

The Role of Bacterial Lipopolysaccharides as Immune Modulator in Vaccine and Drug Development

“…Indeed, this structure is considered the "canonical hTLR4 antagonist", but LPS with similar activity can be found in nature, e.g. LPS derived from Rhodopseudomonas sphaeroides [32,33], R. capsulatus [34,35], Cyanobacterium oscillatoria [36] and Halomonas magadiensis [37]. In general, these compounds often contain pentaacylated Lipid A, with longer acyl chains (> 18 carbons) or lacking phosphate groups.…”