Wagner M, Wagner B, Kronvall G, Björck L
Infect Immun. 1983 Oct;42(1):326-32. doi: 10.1128/iai.42.1.326-332.1983.
The presence and location of receptors for aggregated human beta 2-microglobulin (beta 2m) on the surface of group A, C, and G streptococci were studied by electron microscopic techniques. Ferritin-conjugated aggregates of human beta 2m were used in direct binding experiments. Ferritin-conjugated antibodies against beta 2m were employed in a two-step indirect binding assay where the streptococci were incubated with unlabeled beta 2m aggregates before the addition of antibodies. Similar results were obtained with these two methods. Among tested group C and G strains, some showed binding of beta 2m, whereas others were negative. In group A streptococci, beta 2m binding was localized to filamentous structures typical of M protein. In two M protein-negative group A strains, the reactivity was heterogeneous, revealing a majority of unlabeled, but also some heavily labeled streptococci. Morphologically, these beta 2m-binding bacteria exhibited M protein-like projections in contrast to the smooth surfaces of unlabeled cells.
运用电子显微镜技术研究了A、C、G组链球菌表面人β2微球蛋白（β2m）聚集物受体的存在情况及位置。在直接结合实验中使用了铁蛋白结合的人β2m聚集物。在两步间接结合试验中使用了抗β2m的铁蛋白结合抗体，其中在添加抗体之前，先将链球菌与未标记的β2m聚集物孵育。这两种方法得到了相似的结果。在测试的C组和G组菌株中，一些显示出β2m的结合，而另一些则为阴性。在A组链球菌中，β2m结合定位于M蛋白典型的丝状结构上。在两株M蛋白阴性的A组菌株中，反应性是异质性的，显示出大多数未标记的链球菌，但也有一些标记很重的链球菌。从形态学上看，这些结合β2m的细菌与未标记细胞的光滑表面相比，呈现出M蛋白样的突起。
