• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Molecular Biology >Vibrio cholerae cytolysin recognizes the heptasaccharide core of complex N-glycans with nanomolar affinity
【24h】

Vibrio cholerae cytolysin recognizes the heptasaccharide core of complex N-glycans with nanomolar affinity

机译：Vibrio Cholerae cytolysin认识到含有纳米摩尔亲和力的复合N-聚糖的庚酰核

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Pathogens selectively target host cells using adhesion molecules and secreted virulence factors that may utilize protein, lipid, or carbohydrate ligands on the cell surface. The human intestinal pathogen Vibrio cholerae secretes a pore-forming toxin, V. cholerae cytolysin (VCC), which contains two domains that are structurally similar to known carbohydrate-binding proteins. These tandem domains are attached to the carboxy-terminus of the cytolytic domain and contain a ??-trefoil fold and a ??-prism fold. VCC has been shown to bind glycosylated proteins, and removal of the ??-prism domain leads to a large decrease in lytic activity against rabbit erythrocytes. Despite these clues, the identity of the glycan receptors of VCC and the role of glycan binding in toxin activity remain unknown. To better understand this specificity, we used a combination of structural and functional approaches to characterize the carbohydrate-binding activity of the VCC toxin. We first probed the monosaccharide-binding activity of VCC and demonstrated that the toxin exhibits millimolar affinity for aldohexoses. To understand this specificity, we solved the crystal structure of the VCC ??-prism domain bound to methyl-??-mannose. Next, we utilized a mammalian glycan screen to determine that the ??-prism domain preferentially binds complex N-glycans with a heptasaccharide GlcNAc4Man3 core (NGA2). Fluorescence anisotropy and surface plasmon resonance indicated an approximately 100-nM affinity of the ??-prism domain for the heptasaccharide core. Our results suggest that carbohydrate-binding domains on the VCC toxin facilitate high-affinity targeting of mammalian cell membranes, which may contribute to the ability of VCC to lyse cells at picomolar concentrations. ?2013 Elsevier Ltd. All rights reserved.
机译：病原体使用粘附分子和分泌的毒力因子选择性地靶向宿主细胞，其可利用细胞表面上使用蛋白质，脂质或碳水化合物配体的分泌的毒力因子。人肠道病原体Vibrio Cholerae分泌孔形成毒素，V.霍乱胞嘧啶（Vcc），其含有两个结构上与已知的碳水化合物结合蛋白相似的结构域。这些串联结构域与细胞溶胶结构域的羧基 - 末端附着并含有一个 - 三轴折叠和a ?? - 棱镜折叠。已经显示VCC结合糖基化蛋白质，并除去 - 棱镜结构域导致对兔红细胞的裂解活性大幅下降。尽管这些线索，VCC的聚糖受体的同一性以及甘草结合在毒素活性中的作用仍然未知。为了更好地理解这种特异性，我们使用结构和功能方法的组合来表征Vcc毒素的碳水化合物结合活性。我们首先探讨了VCC的单糖结合活性，并证明毒素对Aldohexs表现出毫摩尔亲和力。为了了解这种特异性，我们解决了与甲基 - α的棱镜结构域的晶域晶体结构求解 - 甘露糖。接下来，我们利用哺乳动物聚糖筛网来确定 - 棱镜结构域优先与庚酰胺GlcNAC4Man3核（NgA2）结合复合的N-聚糖。荧光各向异性和表面等离子体共振表明α-棱镜核心的约100nm亲和力。我们的研究结果表明，VCC毒素上的碳水化合物结合结构域促进了哺乳动物细胞膜的高亲和力靶向，这可能有助于VCC在皮摩尔浓度下溶液细胞的能力。 ？2013年elestvier有限公司保留所有权利。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号