Russell R R
J Gen Microbiol. 1979 Sep;114(1):109-15. doi: 10.1099/00221287-114-1-109.
When heat-killed whole organisms of Streptococcus mutans strain Ingbritt (serotype c) were injected into rabbits, antibodies to at least 12 antigens were detectable by crossed immunoelectrophoresis. In contrast, when rabbits were immunized with organisms which had been subjected to extraction with the detergent sodium dodecyl sulphate (SDS), antibodies to only two protein antigens were found. These two proteins (A and B), while existing in a form apparently closely associated with peptidoglycan, could also be recovered from homogenates of whole organisms after sonication and from culture filtrates. Antigenic material was excreted throughout growth. SDS-polyacrylamide gradient gel electrophoresis showed A to have a molecular weight of 29 000, while B had a molecular weight of 190 000. Antigen B was purified to apparent homogeneity as judged by SDS-polyacrylamide gel electrophoresis and isoelectric focusing. All of six strains of serotype c examined produced antigen B. Strains of serotypes e and f also produce antigenically identical proteins and strains of serotypes d and g produce proteins which cross-reacted with antigen B. Antigen B was specifically precipitated by rabbit antiserum to human heart tissue.
将变形链球菌英布里特菌株（血清型c）的热灭活全菌注射到兔子体内后，通过交叉免疫电泳可检测到针对至少12种抗原的抗体。相比之下，当用经去污剂十二烷基硫酸钠（SDS）提取过的细菌免疫兔子时，仅发现针对两种蛋白质抗原的抗体。这两种蛋白质（A和B），虽然以一种明显与肽聚糖紧密相关的形式存在，但在超声处理后的全菌匀浆以及培养滤液中也能回收得到。在整个生长过程中都会分泌抗原物质。SDS-聚丙烯酰胺梯度凝胶电泳显示A的分子量为29000，而B的分子量为190000。通过SDS-聚丙烯酰胺凝胶电泳和等电聚焦判断，抗原B被纯化至表观均一。所检测的6株血清型c菌株均产生抗原B。血清型e和f的菌株也产生抗原性相同的蛋白质，而血清型d和g的菌株产生与抗原B发生交叉反应的蛋白质。抗原B被兔抗人心脏组织血清特异性沉淀。
