ANALYSIS OF A NOVEL LINKAGE UNIT OF O-LINKED CARBOHYDRATES FROM THE CRYSTALLINE SURFACE-LAYER GLYCOPROTEIN OF CLOSTRIDIUM-THERMOHYDROSULFURICUM S102-70

The surface layer glycoprotein of Clostridium thermohydrosulfuricum S1 02-70 was shown to contain a new type of glycan chain. Different from all known eubacterial glycoproteins, the saccharide moiety consists on ly of six sugar residues without any repeat sequences. Proteolytic dig estion of purified S-layer glycoprotein resulted in isolation of sever al glycopeptide fractions. These are composed of the same hexasacchari de portion but are linked to oligopeptides of different length. One of them contains only a single amino acid. As concluded from chemical an alyses and proton and carbon nuclear magnetic resonance spectroscopy o f this preparation, the hexasaccharide moiety is linked via a novel O- glycosidic linkage. This is a beta-D-glucose residue linked to the phe nolic hydroxyl group of tyrosine in intact S-layer glycoprotein.