title: Immunological relationships between glucosyltransferases synthesizing insoluble glucan from Streptococcus cricetus, Streptococcus sobrinus and Streptococcus downei.
abstract: The Mr values and isoelectric points of glucosyltransferases synthesizing insoluble glucan (GTF-Is) were determined, and the immunological relationships between them studied. The GTF-I enzymes were from Streptococcus cricetus (mutans group serotype a), Streptococcus sobrinus (mutans group serotypes d and g) and Streptococcus downei (mutans group serotype h). By double immunodiffusion tests, the GTF-I enzymes from the three species possessed a common antigenic determinant; in addition, the GTF-I enzymes of serotypes d, g and h shared a further determinant. The S. sobrinus serotypes d and g GTF-I enzymes were immunologically identical. The GTF-I enzymes of S. sobrinus serotypes d and g, and of S. downei, had an Mr of 161,000 and isoelectric points of 4.8-4.9, while S. cricetus GTF-I had a lower Mr (150,000) and a higher isoelectric point (5.2). This suggests that the S. cricetus GTF-I enzyme may lack a sequence of amino acids which include the determinant shared by S. sobrinus and S. downei GTF-I enzymes. Antibodies specific to the determinant shared by all four serotypes inhibited the homologous and heterologous enzymes by 94-100%.
authors.affiliation: Department of Chemistry, National Defense Medical College, Saitama, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tsumori
mesh_terms: D001426:Bacterial Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes; D005936:Glucans / Q000096:biosynthesis*; D005964:Glucosyltransferases / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification / Q000378:metabolism; D007106:Immune Sera; D005779:Immunodiffusion; D007526:Isoelectric Point; D011506:Proteins / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification / Q000378:metabolism; D013291:Streptococcus / Q000201:enzymology*; D016986:Streptococcus sobrinus / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D000939:Epitopes; D005936:Glucans; D007106:Immune Sera; D011506:Proteins; C067118:GTF-I protein, Streptococcus; D005964:Glucosyltransferases; C489364:glucosyltransferase I