Egan W, Liu T Y, Dorow D, Cohen J S, Robbins J D, Gotschlich E C, Robbins J B
Biochemistry. 1977 Aug 9;16(16):3687-92. doi: 10.1021/bi00635a028.
A polysaccharide, antigenically related to group C meningococcus, has been isolated from Escherichia coli strain Bos-12 (016; K92; NM). Like groups B and C meningococcal polysaccharide, the Bos-12 antigen is a pure polymer of sialic acid. 13C NMR studies on the meningococcal group B and C polysaccharides have indicated that the former consists of sialic acid units linked 2 leads to 8- alpha, whereas the latter contains the sialic acid residues linked 2 leads to 9-alpha (Bhattacharjee, A.K., Jennings, H.J., Kenny, C.P., Martin, A., and Smith, I.C.P. (1975), J. Biol. Chem. 250, 1926). Comparison of natural abundance 13C NMR spectra of the Bos-12 polysaccharide with group B and C meningococcal polysaccharides established that Bos-12 was either (a) an equimolar mixture of 2 leads to 8-alpha linked sialic acid homopolymers or (b) a 2 leads to 8-alpha/2 leads to 9-alpha heteropolymer. These possibilities were distinguished in the following manner. The fact that Bos-12 polysaccharide precipitated with anti-group C serum but not with anti-group B serum would seem to exclude a. Further, chemical studies (periodate oxidation followed by tritiated NaBH4 reduction) gave saccharides with a radioactive-labeling pattern expected for alternating 2 leads to 8-alpha/2 leads to 9-alpha sialic acid linkages. Bos-12 is thus an 2 leads to 8/2 lead to 9-alpha heteropolymer.
已从大肠杆菌Bos-12菌株（016；K92；NM）中分离出一种与C群脑膜炎球菌抗原相关的多糖。与B群和C群脑膜炎球菌多糖一样，Bos-12抗原是唾液酸的纯聚合物。对B群和C群脑膜炎球菌多糖的13C NMR研究表明，前者由以2→8-α连接的唾液酸单元组成，而后者含有以2→9-α连接的唾液酸残基（Bhattacharjee，A.K.，Jennings，H.J.，Kenny，C.P.，Martin，A.，和Smith，I.C.P.（1975），《生物化学杂志》250，1926）。将Bos-12多糖的天然丰度13C NMR光谱与B群和C群脑膜炎球菌多糖进行比较，确定Bos-12要么是（a）2→8-α连接的唾液酸均聚物的等摩尔混合物，要么是（b）2→8-α/2→9-α杂聚物。通过以下方式区分了这些可能性。Bos-12多糖能与抗C群血清沉淀而不能与抗B群血清沉淀这一事实似乎排除了a。此外，化学研究（高碘酸盐氧化后用氚化NaBH4还原）得到的糖类具有预期的交替2→8-α/2→9-α唾液酸连接的放射性标记模式。因此，Bos-12是一种2→8/2→9-α杂聚物。
