Affinity capillary electrophoresis for bacterial toxins analysis

FERNÁNDEZ MM, BALDINI E, DE MARZI MC, MALCHIODI EL VESCINA MC.

Amsterdam, the Netherlands

Simposio; 20th Internacional Symposium on Microscale Bioseparations; 2006

Protein-protein interactions are involved in many processes ranging from DNA replication, signal transduction, metabolism control, and viral assembly. The characterization of molecular affinity combined with structural information about the interacting molecules is necessary to understand biological systems mechanism implicated in health and disease. Affinity capillary electrophoresis (ACE) is a powerful tool, where the combination of high-resolution separation and functional molecular characterization, open the possibility to study molecular interactions. Superantigens (SAgs) are a class of immunoestimulatory and disease causing proteins of bacterial or viral origin with the ability to activate large fractions (5-20%) of the T cell population. Activation requires simultaneous interaction of the SAg with the variable (V) b domain of the T-cell receptor (TCR) and with the major histocompatibility complex (MHC) class II molecules on the surface of an antigen presenting cell. This activation leads to production of cytokines such as TNF-a, INF-g and IL-2, which may result in acute toxic shock. The best characterized SAgs are produced by different strains of Staphylococcus aureus and Streptococcus pyogenes. These are implicated in a number of human diseases, including toxic shock syndrome, food poisoning, diabetes mellitus and multiple sclerosis and may be present in prosthesis and food. The aim of the present work was to analyze SAgs and T-cell receptors (TCRs) interaction and obtain a less expensive and fast method to measure analytes in different matrices. For this purpose we have a two-dimensional ACE system where the first dimension is the separation of SAg from other sample components via immobilized TCR specificity followed by separation and detection of the affinity analytes by capillary zone electrophoresis (CZE) as second dimension.