Baker C J, Kasper D L, Davis C E
J Exp Med. 1976 Feb 1;143(2):258-70. doi: 10.1084/jem.143.2.258.
The type III polysaccharide of -roup B Streptococcus has been isolated and purified by a method that employs washing of intact cells at neutral pH. That the polysaccharide prepared by this procedure is the "native" type III antigen is suggested by its molecular size in excess of 10(6) daltons, its degradation by acid and heat treatment to a fragment with immunologic characteristics of the classical HCl antigen, and its type-specific serologic activity. The type III polysaccharide in native form contains sialic acid, galactose, glucose, glucosamine, heptose, and mannose. It is acidic in nature, is resistant to neuramindiase degradation, contains no O-acetyl groups, and does not share antigenic determinants with capsular type K1 antigen of Escherichia coli or Group B polysaccharide antigen of Neiserria meningitidis.
B族链球菌III型多糖已通过一种在中性pH值下洗涤完整细胞的方法进行分离和纯化。通过该程序制备的多糖是“天然”III型抗原,这一点可从其超过10⁶道尔顿的分子大小、经酸和热处理降解为具有经典HCl抗原免疫特性的片段以及其型特异性血清学活性得到证明。天然形式的III型多糖含有唾液酸、半乳糖、葡萄糖、葡糖胺、庚糖和甘露糖。它本质上呈酸性,对神经氨酸酶降解具有抗性,不含O - 乙酰基,并且与大肠杆菌的K1型荚膜抗原或脑膜炎奈瑟菌的B族多糖抗原不共享抗原决定簇。