Structure analysis of lipoglycans and lipoglycan-derived carbohydrates by capillary electrophoresis and mass spectrometry

Abstract

Lipoglycans (lipopolysaccharides, lipoarabinomannans and glycolipids) are unique components of the cell membrane of all cells and the envelope of many bacteria. They play important roles in determining cell-environment interactions, which, however, are only partly understood due to incomplete description of their structural components, lipids and glycans. Capillary electrophoresis is an analytical technique of high separation efficiency and minimum sample requirements and has successfully been used for the analysis of several molecules of biological importance: proteins, nucleic acids and glycoconjugates. In the last years, a few applications of capillary electrophoresis to the analysis of lipoglycans have been reported. Analysis of lipoglycans involves the study of two parameters: intact molecules and carbohydrate parts. The conjunction of capillary electrophoresis and mass spectroscopy not only enhances the detection sensitivity, but also provides structural information on these structurally complex molecules. The interest in the field is rising and the results from the exact determination on the lipoglycan structure are expected to improve our understanding of the molecular mechanism of lipoglycan binding to proteins and cells of host organisms as well as their relationship to the virulence and pathogenesis of bacteria. In this report, an overview of the capillary electrophoresis methods used to analyze and characterize the intact lipoglycans as well as their carbohydrate parts is presented.