The Structure of the Lipid A from the Halophilic Bacterium Spiribacter salinus M19-40T

• Main Authors: Clara Barrau, Flaviana Di Lorenzo, Rodolfo Javier Menes, Rosa Lanzetta, Antonio Molinaro, Alba Silipo
• Format: Article
• Language: English
• Published: MDPI AG 2018-04-01
• Series: Marine Drugs
• Subjects: Spiribacter salinus; halophiles; Ectothiorhodospiraceae; lipopolysaccharide (LPS); lipid A; matrix-assisted laser desorption ionization (MALDI) mass spectrometry; 3-oxotetradecaonic acid
• Online Access: http://www.mdpi.com/1660-3397/16/4/124

The study of the adaptation mechanisms that allow microorganisms to live and proliferate in an extreme habitat is a growing research field. Directly exposed to the external environment, lipopolysaccharides (LPS) from Gram-negative bacteria are of great appeal as they can present particular structural features that may aid the understanding of the adaptation processes. Moreover, through being involved in modulating the mammalian immune system response in a structure-dependent fashion, the elucidation of the LPS structure can also be seen as a fundamental step from a biomedical point of view. In this paper, the lipid A structure of the LPS from Spiribacter salinus M19-40T, a halophilic gamma-proteobacteria, was characterized through chemical analyses and matrix-assisted laser desorption ionization (MALDI) mass spectrometry. This revealed a mixture of mono- and bisphosphorylated penta- to tri-acylated species with the uncommon 2 + 3 symmetry and bearing an unusual 3-oxotetradecaonic acid.