TOXIN-A FROM CLOSTRIDIUM-DIFFICILE BINDS TO RABBIT ERYTHROCYTE GLYCOLIPIDS WITH TERMINAL GAL-ALPHA-1-3GAL-BETA-1-4GLCNAC SEQUENCES
TOXIN-A FROM CLOSTRIDIUM-DIFFICILE BINDS TO RABBIT ERYTHROCYTE GLYCOLIPIDS WITH TERMINAL GAL-ALPHA-1-3GAL-BETA-1-4GLCNAC SEQUENCES
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DOI：
10.1016/0003-9861(87)90561-3
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发表时间：
1987-08-15
影响因子：
3.9
通讯作者：
SMITH, DF
中科院分区：
文献类型：
--
作者：
CLARK, GF;KRIVAN, HC;SMITH, DF
本文研究了艰难梭菌毒素A与兔红细胞糖脂的结合。兔红细胞总脂提取物进行薄层层析和毒素结合糖脂检测使用125 I标记的毒素A在直接结合覆盖技术。两个主要的和几个次要的毒素结合糖脂在兔红细胞中检测到这种方法。主要毒素结合糖脂的结构分析结果与戊糖醇-神经酰胺一致（Gal α 1 - 3Gal β 1 - 4GlcNAc β 1 - 3Gal β 1 -4Glc-Cer）和支链癸酸甘油酯-神经酰胺（Gal α 1 - 3Gal β 1 - 4GlcNAc β 1 -3[Gal α 1 - 3Gal β 1 - 4GlcNAc β 1 -6] Gal β 1 - 4GlcNAc β 1 - 3Gal β 1 -4Glc-Cer）先前被鉴定为兔红细胞中最丰富的两种糖脂。125 I-毒素A与这些糖脂的结合可被牛甲状腺球蛋白、毒素的单特异性抗血清或用α-碘处理糖脂所抑制。半乳糖苷酶。不存在与从犬肠分离的异葡萄糖三己糖神经酰胺（Gal α 1 - 3Gal β 1 -4Glc-Cer）的毒素相互作用，这表明存在于所有已知毒素结合糖缀合物共有的末端Gal α 1 - 3Gal β 1 -4GlcNAc序列中的GlcNAc残基是毒素A特异性识别碳水化合物所必需的。这些观察结果与提出的毒素A对非还原性末端序列Gal α 1 - 3Gal β 1 -4GlcNAc的碳水化合物结合特异性一致。
The binding of Toxin A isolated from Clostridium difficile to rabbit erythrocyte glycolipids has been studied. Total lipid extracts from rabbit erythrocytes were subjected to thin-layer chromatography and toxin-binding glycolipids detected by using 125I-labeled Toxin A in a direct binding overlay technique. Two major and several minor toxin-binding glycolipids were detected in rabbit erythrocytes by this method. The results of structural analyses of the major toxin-binding glycolipids were consistent with a pentasaccharide-ceramide (Gal.alpha.1-3Gal.beta.1-4GlcNAc.beta.1-3Gal.beta.1-4Glc-Cer) and a branched decasaccharide-ceramide (Gal.alpha.1-3Gal.beta.1-4GlcNAc.beta.1-3[Gal.alpha.1-3Gal.beta.1-4GlcNAc.beta.1-6]Gal.beta.1-4GlcNAc.beta.1-3Gal.beta.1-4Glc-Cer) previously identified as the two most abundant glycolipids in rabbit erythrocytes. 125I-Toxin A binding to these glycolipids could be inhibited by bovine thyroglobulin, monospecific antiserum to the toxin, or by treatment of the glycolipids with .alpha.-galactosidase. The absence of toxin interaction with isoglobotriaosylceramide (Gal.alpha.1-3Gal.beta.1-4Glc-Cer) isolated from canine intestine suggested that the GlcNAc residue present in the terminal Gal.alpha.1-3Gal.beta.1-4GlcNAc sequence common to all known toxin binding glycoconjugates is required for carbohydrate-specific recognition by Toxin A. These observations are consistent with the proposed carbohydrate binding specificity of Toxin A for the nonreducing terminal sequence, Gal.alpha.1-3Gal.beta.1-4GlcNAc.