Glycans from Streptococcal Cell Walls: Structural Features of a Diheteroglycan Isolated from the Cell Wall of Streptococcus Bovis

摘要

Two antigenic cell wall glycans were isolated from the cell wall of Streptococcus bovis , strain C3, by sequential extraction with dilute acid. The glycans were purified by fractional precipitation and gel-filtration procedures. Analyses showed that one glycan is a diheteroglycan of glucose and rhamnose and the other is a triheteroglycan of galactose, rhamnose, and 6-deoxy-L-talose. On the basis of evidence from immunologic, chemical and enzymatic experiments, it is suggested that the diheteroglycan is composed of a main chain of rhamnosyl units with many side chains of isomaltosyl units. The isomaltosyl units are the immunodominant groups in the heteroglycan and are responsible for the antigenic specificity of the compound. A serologic typing scheme based on the immunologic responses to these glycans could prove useful in the identification of the group D organisms.