Studies on the Chemical Structure of the Streptococcal Cell Wall

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Although Group G streptococci have been recovered frequently from various sources including the human nasopharynx and the serological classification has been firmly established (1), little attention has been directed to the distinctive immunochemical features of the group-specific carbohydrate antigen. In the present study, therefore, the Group G carbohydrate purified from isolated cell walls, has been characterized and a major chemical determinant of antigenic specificity has been identified.In certain respects the chemical content of the cell walls and carbohydrate antigens of Group G streptococci resembles that of Groups A, A-variant, and C streptococci. The trypsinized cell walls of the latter Groups of streptococci contain two major components: a mucopeptide matrix consisting of N-acetylmuramic acid, N-acetylglucosamine, and four amino acids; and the groupspecific carbohydrate, exterior to the mucopeptide, which is composed of rhamnose and N-acetylhexosamine (2, 3). Data to be reported here indicate that the constituent sugars of Group G carbohydrate are rhamnose, galactosamine, and galactose while the composition of the mucopeptide is similar to that of the other three groups of streptococci. Materials and MethodsStreptococcal Strains.--Group G cell walls were prepared from strains D166B, B763A, and B549 obtained from Dr. Rebecca C. Lancefield, The Rockefeller Institute. Preparation of Cell Walls and C-roup-SpeciJ~Carbohydrate.--Cell walls were prepared by previously described methods (4). The group carbohydrate was extracted from the cell walls by the formamide procedure (5).Analytical Methods.--Analyses for rhamnose, muramic acid, glucosamine, galactosamine, and the amino acids were performed by previously described methods (3, 4).

Section: Discussionsupporting

confidence: 67%

“…The chemical composition of the mucopeptide of Group G was essentially similar to that of Groups A and C streptococci (3,4).…”

Section: Discussionmentioning

confidence: 72%

Immunochemical Studies on the Specific Carbohydrate of Group G Streptococci

Curtis

Krause

1964

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“…ies indicate that cell wall dissolving enzymes release dialyz~ble and non-dialyzable soluble mucopepfide in addition to the carbohydrate (12). Similar experiments were undertaken to identify the soluble substances of Type 1 cell walls after autolysis and lysis with lysozyme.…”

Section: Split Products Rdeased From Cell Walls By Enzymatic Aaion~pmentioning

confidence: 99%

The Cell Walls of Group D Streptococci

Bleiweis

Krause

1965

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The type-specific carbohydrates of Group D streptococci are components of the cell wall and are the structural and chemical counterparts of the specific carbohydrates of Groups A, B, C, and G streptococci (1). Although a number of serologic types of Group D streptococci have been identified, the immunochemical basis for this antigenic classification has not been elucidated (2) The Group D antigen, unlike the group-specific carbohydrates for most of the other streptococcal groups, is a cytoplasmic constituent and not a cell wall component (1, 3), and has been identified as a glucose-glucosyl glycerol teichoie acid (4). Isolation and purification of the type antigen is simplified by the fact that Group D cell wails are devoid of the group antigen. Preparation of Cell Wal/s.--Cell walls were prepared using the Braun homogenizer as described previously (5). Methods and Materials

“…The three streptococcal carbohydrate antigens, Group A, Group A-variant, and Group C, possess a similar branched rhamnose polymer. The Group A carbohydrate specificity is dependent upon terminal N-acetylglucosaminide residues (13), while that of Group C is dependent upon terminal N-acetylgalactosaminide 1170 EMERGENCE OF ANTIBODIES DURING IMMUNIZATION residues (14). The antigenic specificity of the Group A-variant carbohydrate resides in the rhamnose polymer itself (15).…”

Section: (From the Rockefeller University New York 10021)mentioning

confidence: 99%

The Emergence of Antibodies With Either Identical or Unrelated Individual Antigenic Specificity During Repeated Immunizations With Streptococcal Vaccines

Eichmann

Braun

Feizi

et al. 1970

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Electrophoretically monodisperse antibody components in rabbit antisera to the carbohydrates of the Groups A and C streptococci have been examined for their individual antigenic specificity. In these antibody components which were isolated by preparative electrophoresis, individual antigenic specificity was confined to the specific antibody and was absent in the nonantibody γ-globulin. Radioprecipitation experiments and the use of immune absorbent columns constructed from goat anti-antisera, which had been absorbed with fraction II, revealed that all the specific antibody in an electrophoretically monodisperse component was reactive with the homologous anti-antibody. Antibodies with either identical or distinct individual antigenic specificities may occur in the same rabbit with repeated immunizations. Antibodies with identical antigenic specificity had identical electrophoretic mobility, whereas antibodies with unrelated antigenic specificities had distinct electrophoretic mobilities. In the interval between immunizations, if antibody to the carbohydrate antigen was absent, there was no detectable antibody with individual antigenic specificity.