Takada K, Shiota T, Ikeda T
Department of Microbiology, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
Biochim Biophys Acta. 1990 Mar 26;1033(3):273-6. doi: 10.1016/0304-4165(90)90132-g.
The polysaccharide antigen (designated SI) from Streptococcus sobrinus 6715 (serotype g) which cross-reacts with serotype a and d strains was purified by a specific anti-cross-reactive g-a antibody-Sepharose 4B affinity column. By a double immunodiffusion analysis, the SI antigen was found to lack the serotype-specific g site, but contained the cross-reactive sites g-a, g-d and g-(a-d) on a single molecule. Polysaccharide SI was composed of galactose, glucose and rhamnose in a molar ratio of 4.79:1.52:1. The results of the test on the inhibition of the precipitin reaction and methylation analysis suggested that the cross-reactive site g-a of the SI antigen appeared to have two regions, one containing galactose residues and the other, beta-linked glucose residues.
来自远缘链球菌6715（血清型g）的与血清型a和d菌株发生交叉反应的多糖抗原（命名为SI），通过特异性抗交叉反应性g-a抗体-琼脂糖4B亲和柱进行纯化。通过双向免疫扩散分析发现，SI抗原缺乏血清型特异性g位点，但在单个分子上含有交叉反应位点g-a、g-d和g-(a-d)。多糖SI由半乳糖、葡萄糖和鼠李糖以4.79:1.52:1的摩尔比组成。沉淀素反应抑制试验和甲基化分析结果表明，SI抗原的交叉反应位点g-a似乎有两个区域，一个区域含有半乳糖残基，另一个区域含有β-连接的葡萄糖残基。
