ABSTRACT
The specific capsular polysaccharide of type 45 Streptococcus pneumoniae was isolated in pure form by chemical and chromatographic methods and found to be a high-molecular-weight, glycosidically linked polymer of a hexasaccharide repeating unit composed of D-galactose (2 mol), L-rhamnose (1 mol), N-acetyl-D-glucosamine (1 mol), N-acetyl-D-galactosamine (1 mol), N-acetyl-L-fucosamine (1 mol), and phosphate (1 mol).
Subject(s)
Polysaccharides, Bacterial/isolation & purification , Streptococcus pneumoniae/analysis , Chemical Phenomena , Chemistry , Molecular WeightABSTRACT
An antigenic complex has been isolated in a highly purified from from the Melvin strain of Neisseria gonorrhoeae. The complex has a molecular weight of 9.3 x 10(6) and on sodium dodecyl sulfate-polyacrylamide gel electrophoresis was found to consist of several subunits; the most predominant had the following molecular weights: 110,000, 94,000, 68,000, a smear containing (52,000, 48,000, and 44,000), 42,000, 36,000, 29,000, 28,000, 26,000, and 12,000 comprising 89% of the total protein. With the exception of the subunit of molecular weight 110,000, no change in the content or the mobility of other subunits was observed when beta-mercaptoethanol was omitted from the denaturation solution of sodium dodecyl sulfate electrophoresis. Amino acid analysis of the complex showed a predominance of hydrophobic amino acids. These data implicated noncovalent interactions between the subunits. When the cells were labeled with fluorescamine it was possible to obtain a fluorescent complex with identical properties. Among several buffers used for the isolation of the complex, 0.2 M tris(hydroxymethyl)aminomethane buffer (pH 7.5) gave maximum yield with low amounts of lipopolysaccharide and phospholipid; the choice of the buffer for column chromatography did not seem to make any difference. The high protein content and low amounts of lipopolysaccharide and phospholipid are characteristic properties of the complex.
Subject(s)
Antigens, Bacterial/isolation & purification , Bacterial Proteins/immunology , Neisseria gonorrhoeae/immunology , Amino Acids/analysis , Bacterial Proteins/isolation & purification , Chromatography, Affinity , Chromatography, Gel , Lipopolysaccharides/analysis , Macromolecular Substances , Membrane Proteins/immunologyABSTRACT
A lipopolysaccharide was isolated from Neisseria meningitidis group B by phenol/water extraction and purified by differential ultracentrifugation. This preparation exhibited endotoxic properties as shown by the limulus-lysate assay. Mild acid hydrolysis of the lipopolysaccharides yielded a lipid A fraction and a polysaccharide fraction. The lipid A fraction contained fatty acids, phosphorus and glucosamine. Analysis of the polysaccharide fraction revealed the presence of glucose, galactose, glucosamine, 2-keto-3-deoxyoctonic acid and phosphorus. There was no heptose.