Isolation and characterization of type IV group B Streptococcus capsular polysaccharide.
Isolation and characterization of type IV group B Streptococcus capsular polysaccharide.
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IV 型 B 族链球菌荚膜多糖的分离和表征。
DOI：
10.1128/iai.57.4.1089-1094.1989
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发表时间：
1989
影响因子：
3.1
通讯作者：
Kasper,DL
中科院分区：
文献类型：
--
作者：
Wessels,MR;Benedí,WJ;Jennings,HJ;Michon,F;DiFabio,JL;Kasper,DL
抗原性不同的血清型IV型最近被添加到B组链球菌（GBS）的公认血清型中。我们从原型IV型GBS菌株中分离并纯化了荚膜多糖抗原。IV型荚膜多糖与IV型GBS生物体的兔抗血清形成沉淀线，但与GBS血清型Ia、Ib、II或III生物体的抗血清不形成沉淀线。酶联免疫吸附试验抑制实验表明IV型抗血清与其他血清型GBS无交叉反应。从具有变溶菌素的细菌细胞中释放的荚膜多糖和从培养物上清液中分离的荚膜多糖在Sepharose CL-6B上具有相似的洗脱曲线，Kav为0.30，估计Mr为200，000。发现纯化的IV型多糖含有半乳糖、葡萄糖、N-乙酰葡糖胺和N-乙酰神经氨酸（唾液酸）作为排他性糖。该多糖含有23%（重量）的唾液酸和半乳糖，葡萄糖和N-乙酰葡糖胺的相对比例为（1）：1.10：0.55。这些结果与含有摩尔比为2：2：1：1的半乳糖、葡萄糖、N-乙酰葡糖胺和唾液酸的六个单糖残基的重复结构相容。与Ia型、II型和III型GBS多糖不同，IV型多糖的去唾液酸化产生的抗原在针对同源抗血清的琼脂双扩散中与天然IV型抗原形成同一性线。该结果表明，唾液酸对IV型抗原的免疫决定簇结构并不像对其他GBS荚膜类型那样重要。
An antigenically distinct serotype, type IV, has recently been added to the recognized serotypes of group B streptococci (GBS). We isolated and purified the capsular polysaccharide antigen from a prototype type IV GBS strain. The type IV capsular polysaccharide formed a precipitin line with rabbit antiserum to type IV GBS organisms but not with antiserum to organisms of GBS serotype Ia, Ib, II, or III. Enzyme-linked immunosorbent assay inhibition experiments showed no cross-reaction between type IV antiserum and other GBS serotypes. Capsular polysaccharide released from the bacterial cells with mutanolysin and that isolated from the culture supernatant had similar elution profiles on Sepharose CL-6B, with a Kav of 0.30 and an estimated Mr of 200,000. The purified type IV polysaccharide was found to contain galactose, glucose, N-acetylglucosamine, and N-acetylneuraminic acid (sialic acid) as exclusive sugars. The polysaccharide contained 23% (by weight) sialic acid and galactose, glucose, and N-acetylglucosamine in a relative ratio of (1):1.10:0.55. These results are compatible with a repeating structure of six monosaccharide residues containing galactose, glucose, N-acetylglucosamine, and sialic acid in a molar ratio of 2:2:1:1. Unlike type Ia, II, and III GBS polysaccharides, desialylation of the type IV polysaccharide produced an antigen which formed a line of identity with the native type IV antigen in double diffusion in agar against homologous antiserum. This result suggests that sialic acid is not as critical to the immunodeterminant structure of the type IV antigen as it is for other GBS capsular types.