Structure and immunological activity of the lipopolysaccharide isolated from the species Alkalimonas delamerensis

We have defined the complete structure and assessed the biological activity of the lipopolysaccharide (LPS) from Alkalimonas delamerensis, an alkaliphilic bacterium isolated from soda lakes in China and East Africa. The structural determination, which was achieved by the use of chemical, spectroscopic and spectrometric approaches, indicates a novel Rough type lipopolysaccharide that is rich in negatively charged groups in the lipid A inner core region. The proinflammatory activity of the pure lipopolysaccharide has also been defined by testing the LPS as a stimulant in human HEK293 cells, which express the CD14/MD2/TLR4 complex (HEK293-hTLR4), and in bone marrow-derived macrophages. The structure and the biological activity of the lipopolysaccharide isolated from the alkaliphilic bacterium Alkalimonas delamerensis is reported. The lipopolysaccharide is rich in negatively charged groups in the lipid A core and exerts a strong proinflammatory activity through TLR4, likely driven by the high degree of acylation of the lipid A portion and the consistent phosphorylation pattern. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.