Weerkamp A H, Jacobs T
Infect Immun. 1982 Oct;38(1):233-42. doi: 10.1128/iai.38.1.233-242.1982.
Three cell wall-associated protein antigens (antigens b, c, and d) were isolated from mutanolysin-solubilized cell walls of Streptococcus salivarius HB and purified to apparent homogeneity by a combination of ion-exchange chromatography, gel filtration, and immunoadsorption chromatography. Antigens b and c were also isolated from culture supernatants. Antigen b consisted of more than 80% protein and had an apparent molecular weight as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of 320,000. Antigen c consisted of 57% protein, about 30% neutral sugar, and about 13% amino sugar, and its glycoprotein nature was confirmed by specific staining techniques. During sodium dodecyl sulfate-polyacrylamide gel electrophoresis antigen c resolved into two or more bands, depending on the source or the isolation procedure, in the molecular weight range from 220,000 to 280,000. Antigen d consisted of 95% protein and was observed in sodium dodecyl sulfate-polyacrylamide gel electrophoresis as two bands with molecular weights of 129,000 and 121,000. Under nondenaturing conditions all three antigens had molecular weights in the range from 1 x 10(6) to 3 x 10(6) as determined by gel filtration. The amino acid compositions of antigens b, c, and d were characterized by low amounts of basic amino acids and relatively high levels of nonpolar amino acids. Among oral streptococcal species antigens b and c were virtually restricted to strains of S. salivarius and most often to serotype I strains. Antigen b was recognized as the factor that mediates coaggregation of S. salivarius with Veillonella strains. The purified protein retained its biological activity. Antigen c could be linked to functions relating to adhesion of the streptococci to host tissues on the basis of its absence in mutant strains and blocking by specific antisera. The purified molecule had no detectable biological activity. Antigen d could not be linked to an established adhesion function.
从唾液链球菌HB的变溶菌素增溶细胞壁中分离出三种细胞壁相关蛋白抗原（抗原b、c和d），并通过离子交换色谱、凝胶过滤和免疫吸附色谱相结合的方法将其纯化至表观均一。抗原b和c也从培养上清液中分离得到。抗原b蛋白质含量超过80%，通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳测定其表观分子量为320,000。抗原c由57%的蛋白质、约30%的中性糖和约13%的氨基糖组成，其糖蛋白性质通过特异性染色技术得以证实。在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳过程中，抗原c根据来源或分离程序不同，在分子量范围为220,000至280,000时可分解为两条或更多条带。抗原d由95%的蛋白质组成，在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳中表现为两条带，分子量分别为129,000和121,000。在非变性条件下，通过凝胶过滤测定，所有三种抗原的分子量范围为1×10⁶至3×10⁶。抗原b、c和d的氨基酸组成特点是碱性氨基酸含量低，非极性氨基酸含量相对较高。在口腔链球菌属中，抗原b和c实际上仅限于唾液链球菌菌株，且最常见于I型血清型菌株。抗原b被认为是介导唾液链球菌与韦荣氏菌属菌株共聚集的因子。纯化后的蛋白质保留了其生物学活性。基于其在突变菌株中不存在以及被特异性抗血清阻断，抗原c可能与链球菌黏附于宿主组织的功能有关。纯化后的分子未检测到生物学活性。抗原d与已确定的黏附功能无关。
