复合和结构研究ZwitterionicBacteroides fragilis 多糖A1片段
Zhen Wang1,2, Ana Poveda3, Qingju Zhang1,2
1Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands.
Journal of the American Chemical Society
|June 13, 2023
概括
研究人员从细菌菌体 (Bacteroides fragilis) 中合成了Zwitterionic多糖体 (ZPS) 片段, 揭示了它们独特的螺旋结构. 这一突破使得研究这些碳水化合物抗原如何与MHC-II等免疫受体相互作用成为可能.
科学领域:
- 碳水化合物化学
- 免疫学
- 结构生物学
背景情况:
- 基多糖 (ZPS) 具有正负电荷,可通过MHC-II呈现激活T细胞.
- ZPS与MHC-II的结合机制尚不清楚,因此需要明确的碎片进行结构分析.
研究的目的:
- 为了实现第一个完全合成 Bacteroides fragilis PS A1 片段.
- 阐明负责它们与免疫受体的类相互作用的ZPS的结构特征.
主要方法:
- 开发了一种新型的合成路径,使用"环反转"的银河胺基构造块进行立体选择性糖化.
- 采用基保护组策略,并使用直角的基因手柄进行功能化.
- 使用详细的结构研究来确定合成的寡糖碎片的构造.
主要成果:
- 成功合成了多达12个单糖的ZPS A1片段,
- 显示组装的寡糖体采用曲的结构,在较大的多糖体中形成左侧螺旋.
- 证明带正电荷的氨基基团在螺旋结构上是向外导向的.
结论:
- 合成提供了明确的ZPS片段,对于理解ZPS-MHC-II相互作用至关重要.
- 发现的螺旋结构为ZPS如何呈现功能组提供了洞察力.
- 这些发现为原子级研究ZPS在免疫反应中的作用模式铺平了道路.
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