BIOSENSORS BASED ON RECEPTORS : IMMUNOSENSORS ON THE BASIS OF LIPOPEPTIDES

Abstract

Covalent attachment of the lipoamino acid N-palmitoyl-S-[2,3-bis(palmitoyloxy)-propyl]- [2RS]-cysteine (Pam3Cys-OH) (10) - a synthetic analogue to the N-terminal part of lipoprotein from the outer membrane of E. coli (11) - to peptidic antigens (epitopes) results in lipopeptideconjugates with interesting immunological and biophysical properties. Lipopeptides are able to activate B-lymphocytes (10,12), macrophages (13) and neutrophilic cells (14) and induce the production of specific antibodies against the antigenic peptide (15). The developmentof a fully synthetic vaccine against foot-and-mouth disease (FMDV) (16) as well as the in vivo-priming of cytotoxic T-lymphocytes (17) demonstrate the immunological power of lipopeptides. Biophysical investigations with labelled lipopeptides (18-20) show that lipopeptides have a high tendency to insert into membranes of living cells and into artificial phospholipid membranes (vesicles). The high affinity of lipopeptides to hydrophobic surfaces has been used for the coating of polystyrene microtiter plates in an assay (ELISA) for the distinction between HIV-1 and HIV-2 (21).