Group B, type III streptococcal cell wall: composition and structural aspects revealed through endo-N-acetylmuramidase-catalyzed hydrolysis.
Cell walls from a group B, type III streptococcus strain were prepared, purified by extraction with sodium dodecyl sulfate, and solubilized by the M-1 fraction of mutanolysin, an endo-N-acetylmuramidase obtained from Streptomyces globisporus. The lysate was resolved into three fractions by ion-exchange chromatography: a fraction containing peptidoglycan (PG) fragments, free of neutral and acidic sugars and of phosphate; a complex of PG fragments and group B-specific polysaccharide; and a complex of PG fragments and group B-specific polysaccharide and type III-specific polysaccharide. The PG-polysaccharide complexes were large and heterogeneous in molecular size. When subjected to base-catalyzed beta-elimination, both complexes were disintegrated, and polysaccharides and low-molecular-weight PG fragments could then be separated by gel filtration. The low-molecular-weight PG fragment-containing fraction contained muramic acid, glucosamine, alanine, lysine, glutamic acid, and serine in molar ratios (to lysine) of 0.92:0.98:3.01:1.00:1.00:0.05. Wall-derived, purified group polysaccharide contained rhamnose, galactose, glucosamine, and phosphorus in molar ratios (to galactose) of 5.03:1.00:1.00:1.05. It also contained an unidentified sugar. Wall-derived, purified type III polysaccharide contained galactose, glucosamine, glucose, and N-acetylneuraminic acid in molar ratios (to glucose) of 1.94:0.85:1.00:1.39. On a dry-weight basis, the whole wall lysate contained 19.8 and 20.6% of group and type polysaccharide, respectively. Neither glycerol nor ribitol was found, and all of the cell wall phosphorus was accounted for as polysaccharide, indicating the absence of a wall teichoic acid.
D000596:Amino Acids / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis; D002473:Cell Wall / Q000032:analysis; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D006026:Glycoside Hydrolases / Q000378:metabolism; D010457:Peptidoglycan / Q000032:analysis*; D011135:Polysaccharides, Bacterial / Q000032:analysis*; D013292:Streptococcus agalactiae / Q000032:analysis* / Q000648:ultrastructure
D000596:Amino Acids; D002241:Carbohydrates; D010457:Peptidoglycan; D011135:Polysaccharides, Bacterial; D006026:Glycoside Hydrolases; C026255:endo-N-acetylmuramidase