A water-soluble fragment of Micrococcus lysodeikticus cell wall.

A fragment of Micrococcus lysodeikticus cell wall was obtained by extraction of walls with water, dimethylformamide or dimethyl sulfoxide. The water-soluble polymer was obtained from the cell walls prepared either with or without trypsin treatment of the cell. This fragment was studied by the Smith periodate oxidation, methylation, mild acid treatment and enzymic procedures. The polymer consists of polysaccharide chains composed of (1-->4)-O-(2-acetamido-2-deoxy-beta-D-mannopyranosyluronic acid)-(1-->6)-O-alpha-D-glucopyranosyl residues. The polysaccharide chain is linked to C-6 of a 2-acetamido-3-O-(D-1-carboxyethyl)-2-deoxy-beta-D-gluco-pyranosyl residue of a peptidoglycan chain composed of repeating (1-->4)-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-(1-->4)-[2-acet ami do-3-O-(D-1-carboxyethyl)-2-deoxy-beta-D-glucopyranosyl] residues. The water-soluble cell-wall fragment was also observed in the-culture medium of Micrococcus lysodeikticus and was also extractable from the cells in minor quantity.