Capillary electrophoresis of bacterial (lipo)polysaccharides

Lipopolysaccharides (LPSs) are major components of the outer membrane of gram-negative bacteria and, along with some acidic polysaccharides, are important macromolecules belonging to bacteria. The recent emergence of modern analytical tools for their study has produced a virtual explosion in the field of glycomics. Capillary electrophoresis (CE), due to its high resolving power and sensitivity, has been useful in the analysis of intact bacterial acidic polymers and derived oligo- and disaccharides as such as LPS affording concentration and structural characterization data essential for understanding their biological functions. Furthermore, the coupling of CE with mass spectrometry (MS) provides a powerfull approach far rapid identification of target analytes, i.e. bacterial LPSs, present in biological matrices, and for their structural characterization. This methodology facilitates the determination of closely related LPS glycoform and isoform families by exploiting differences in their unique molecular conformations and ionic charge distributions by electrophoretic separation. On-line CE-MS also provides an additional tool to improve detection limits successfully applied to directly probe oligosaccharide LPS glycoform populations of bacteria. In this review, the state of art of CE, CE-MS and tandem MS methods for screening LPSs and bacterial polysaccharides and derived oligosaccharides and disaccharides will be discussed.