Extraction, Purification, and Chemical and Immunological Properties of the Streptococcus mutans Group “a” Polysaccharide Cell Wall Antigen

Abstract

An antigen of Streptococcus mutans has been extracted from HS6 (group "a") whole cells and repeatedly fractionated by Sephadex chromatography. The antigen is shown to be a polysaccharide and contains the S. mutans group "a" antigenic site and also a second antigenic site which is common to "a" strains and 2 of 3 group "d" strains. Immunological electrophoretic and chromatographic data indicate that the two sites exist in a single molecule. The polysaccharide has a molecular weight of 107,000 and is composed of glucose, galactose, glucosamine, and galactosamine. No significant quantities of lipid, phosphorus, glycerol, or ribitol are present. Immunological specificity of the group "a" polysaccharide site depends primarily on a D-glucose D-glucose sequence, the "a-d" site on a terminal D-galactose. Water at 100 C and pepsin (pH 2.5) at room temperature are very effective in extracting the polysaccharide from lyophilized S. mutans cells. Trypsin and lysozyme are less effective. The antigen-antibody combining site appears to be located at the cell wall surface. A small quantity of enzyme-resistant protein (5%) is firmly linked to the antigen and is considered to be a remnant of a protein to which the polysaccharide is attached in the cell wall. The composition of the protein does not identify it as a part of the peptidoglycan. No reaction to the purified polysaccharide is obtained with antisera specific for teichoic acid glycerophosphate polymers from streptococci, staphylococci, or lactobacilli. "a-d" antigen. 190 on July 31, 2020 by guest http://iai.asm.org/ Downloaded from

Chemical Composition of Streptococcus mutans Cell Walls and Their Susceptibility to Flavobacterium L‐11 Enzyme

“…Other non-peptidoglycan components, glucose, rhamnose, and/or galactose, were variably detected in S. mutans cell walls (Table 3). These results are consistent with previous observations (1,16), and support the findings that the serotype a, d, and g antigens are polymers of galactose and glucose (19,26,27,34), while the serotype c, e, and f antigens are polymers of glucose and rhamnose (10,14,48). Serotype b antigen has been shown to be a polymer of rhamnose and galactose (33).…”

Purification and immunochemical characterization of type e polysaccharide antigen of Streptococcus mutans

“…4. This type of multiple specificity on the single antigen molecule has been demonstrated in the polysaccharide antigens from type a and d S. mutants (17,27) and type f S. mutans (8a).…”

“…Strains of Streptococcus mutans, an agent that develops dental caries in animals and probably humans, have been subdivided into seven immunological types (2,30). The antigens of types a (27), b (26), c (16,42), d (13,18) and f (8a) are located in the cell wall and are polysaccharides composed of rhamnose and glucose (type c and f), rhamnose and galactose (type b), and glucose and galactose (types a and d). S. mutans strains do not show any immunological cross-reaction with the streptococcal groups except group E (3,30).…”

Serotype‐Dependent Inhibition of Glucan Synthesis and Cell Adherence of Streptococcus mutans by Antibody against Glucosyltransferase of Serotype e S. mutans

“…Antibodies against GTase(s) inhibit enzyme activity (1,6,7,9,10,21,23,35) and result in the reduction of experimental caries of S. mutans in rats (37). 5. mutans has been classified into seven serotypes (3,14,15,31) of which immunological specificity is based on the cell wall polysaccharide (12,17,22,23,26,27,40). Questions have arisen concerning the immunological properties of GTase in view of the importance of this enzyme in dental caries and its possible use as an immunizing agent.…”