REVERSIBLE CROSS-LINKING OF CRYSTALLINE BACTERIAL SURFACE-LAYER GLYCOPROTEINS THROUGH THEIR GLYCAN CHAINS

After periodate oxidation and incubation with dithiodipropionic acid d ihydrazide cross-linking of the crystalline surface layer (S-layer) gl ycoproteins of Clostridium thermohydrosulfuricum L111-69 and Bacillus alvei CCM 2051 was achieved specifically through the glycan chains. Th e cross-linked S-layers were used for the immobilization of chemically synthesized, spacer-linked, tumour-associated T-disaccharide [betaGal (1-->3)alphaGalNAc]. Electron microscopical evaluation of the resultin g conjugates showed densely packed, multilayered S-layer structures lo aded with the immobilized ligand. After reductive cleavage of the disu lphide bond of dithiodipropionic acid by dithiothreitol, monomeric hap tenated S-layer conjugates could be obtained. Both the cross-linked an d the monomeric type of conjugate might be useful for assessment of sp ecific immune responses, which, in general, can be elicited by those a rtificial antigens.